Tüm alıştırma soruları

2131 soru

Soru 121Soru

In the xyxy-plane, line kk passes through the points (1,2)(1, -2) and (5,6)(5, 6). Line mm is the perpendicular bisector of the line segment connecting (1,2)(1, -2) and (5,6)(5, 6). Which of the following statements must be true? Select all that apply.

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Cevap: Line mm passes through the point (7,0)(7, 0).; Line mm has a yy-intercept of (0,3.5)(0, 3.5).; The distance from the origin (0,0)(0, 0) to the midpoint of the line segment is 13\sqrt{13}.

Cevap

The statements asserting that line mm passes through (7,0)(7, 0), that line mm has a yy-intercept of (0,3.5)(0, 3.5), and that the distance from the origin to the midpoint of the segment is 13\sqrt{13} are all true.
Line kk has slope 6(2)51=2\frac{6 - (-2)}{5 - 1} = 2 and segment midpoint (3,2)(3, 2). Line mm, as the perpendicular bisector, has slope 12-\frac{1}{2} and equation y=12x+3.5y = -\frac{1}{2}x + 3.5. Substituting x=7x = 7 gives y=0y = 0, so (7,0)(7, 0) lies on line mm. Substituting x=0x = 0 gives y=3.5y = 3.5, confirming the yy-intercept. Finally, the distance from (0,0)(0,0) to the midpoint (3,2)(3,2) is 32+22=13\sqrt{3^2 + 2^2} = \sqrt{13}. Thus, all three of these statements are correct.

Adım Adım Çözüm

1
Find the midpoint and slope of the segment connecting (1,2)(1, -2) and (5,6)(5, 6).
Midpoint M=(1+52,2+62)=(3,2)M = \left(\frac{1+5}{2}, \frac{-2+6}{2}\right) = (3, 2). Slope of segment mk=6(2)51=84=2m_k = \frac{6 - (-2)}{5 - 1} = \frac{8}{4} = 2.
Line mm is the perpendicular bisector, so it passes through midpoint MM and has a slope perpendicular to mkm_k.
2
Determine the slope and equation of line mm.
Perpendicular slope mm=1mk=12m_m = -\frac{1}{m_k} = -\frac{1}{2}. Point-slope equation through (3,2)(3, 2): y2=12(x3)    y=12x+72y - 2 = -\frac{1}{2}(x - 3) \implies y = -\frac{1}{2}x + \frac{7}{2}.
Perpendicular lines have negative reciprocal slopes.
3
Evaluate each given statement against the calculated values.
Line mm contains (7,0)(7, 0) because 0=12(7)+720 = -\frac{1}{2}(7) + \frac{7}{2}. The yy-intercept is (0,3.5)(0, 3.5). Distance from (0,0)(0,0) to (3,2)(3,2) is 32+22=13\sqrt{3^2 + 2^2} = \sqrt{13}. Statements claiming slope is 22 or that line mm is parallel to 2xy=42x - y = 4 are incorrect.
Determines which statements satisfy all mathematical conditions.

Anahtar Kavram

Perpendicular Bisectors, Slopes of Perpendicular Lines, and Distance Formula
Soru 122Soru

The quadratic equation 2x2+px+q=02x^2 + px + q = 0, where pp and qq are constants, has roots rr and ss. The quadratic equation x2+(p2)x+24=0x^2 + (p - 2)x + 24 = 0 has roots r+2r + 2 and s+2s + 2. What is the value of qq?

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Cevap: 32

Cevap

The value of qq is 32.
Applying Vieta's formulas to 2x2+px+q=02x^2 + px + q = 0 gives r+s=p/2r + s = -p/2 and rs=q/2rs = q/2. For the second equation x2+(p2)x+24=0x^2 + (p-2)x + 24 = 0, the sum of roots is (r+2)+(s+2)=(p2)(r+2) + (s+2) = -(p-2), which simplifies to (r+s)+4=2p(r+s) + 4 = 2 - p. Substituting r+s=p/2r+s = -p/2 yields p/2+4=2p-p/2 + 4 = 2 - p, solving to p=4p = -4 and r+s=2r+s = 2. The product of roots for the second equation is (r+2)(s+2)=rs+2(r+s)+4=24(r+2)(s+2) = rs + 2(r+s) + 4 = 24. Substituting rs=q/2rs = q/2 and r+s=2r+s = 2 gives q/2+4+4=24q/2 + 4 + 4 = 24, which simplifies to q/2=16q/2 = 16 and q=32q = 32.

Adım Adım Çözüm

1
Express the sum and product of roots rr and ss in terms of pp and qq using Vieta's formulas.
r+s=p2r + s = -\frac{p}{2} and rs=q2rs = \frac{q}{2}.
For a quadratic equation ax2+bx+c=0ax^2 + bx + c = 0, the sum of the roots is ba-\frac{b}{a} and the product is ca\frac{c}{a}.
2
Relate the sum of the shifted roots (r+2)(r + 2) and (s+2)(s + 2) to the coefficients of the second quadratic equation.
(r+2)+(s+2)=(p2)    (r+s)+4=2p(r + 2) + (s + 2) = -(p - 2) \implies (r + s) + 4 = 2 - p.
The coefficient of xx in x2+(p2)x+24=0x^2 + (p - 2)x + 24 = 0 is (p2)(p - 2), so the sum of its roots equals (p2)-(p - 2).
3
Substitute r+s=p2r + s = -\frac{p}{2} into the sum relation to determine pp.
p2+4=2p    p2=2    p=4-\frac{p}{2} + 4 = 2 - p \implies \frac{p}{2} = -2 \implies p = -4.
Solving the linear equation for pp yields p=4p = -4, which means r+s=2r + s = 2.
4
Expand the product of the shifted roots (r+2)(s+2)=24(r + 2)(s + 2) = 24 and solve for qq.
rs+2(r+s)+4=24    q2+2(2)+4=24    q2+8=24    q=32rs + 2(r + s) + 4 = 24 \implies \frac{q}{2} + 2(2) + 4 = 24 \implies \frac{q}{2} + 8 = 24 \implies q = 32.
Substituting rs=q2rs = \frac{q}{2} and r+s=2r + s = 2 isolates qq, yielding q=32q = 32.

Anahtar Kavram

Relating roots and coefficients of quadratic equations using Vieta's formulas and algebraic expansion.
Soru 123Soru

A research study records five numerical observations: 1212, 1616, 2020, 2020, and xx, where xx is a positive integer. If the arithmetic mean of these five observations is equal to their median, which of the following values could be xx? Select all such values.

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Cevap: 1212; 1717; 3232

Cevap

The possible values of xx are 1212, 1717, and 3232.
The mean of the dataset is given by 68+x5\frac{68+x}{5}. Depending on where xx falls relative to the sorted known values (12,16,20,2012, 16, 20, 20), the median can be 1616 (if x16x \le 16), xx (if 16x2016 \le x \le 20), or 2020 (if x20x \ge 20). Equating the mean to the median in each case yields three valid solutions: x=12x = 12, x=17x = 17, and x=32x = 32.

Adım Adım Çözüm

1
Express the arithmetic mean in terms of xx.
The sum of the five numbers is 12+16+20+20+x=68+x12 + 16 + 20 + 20 + x = 68 + x. Therefore, the mean is 68+x5\frac{68 + x}{5}.
The mean of nn numbers is the total sum divided by nn.
2
Analyze Case 1 where x16x \le 16.
The sorted dataset is x,12,16,20,20x, 12, 16, 20, 20 (or 12,x,16,20,2012, x, 16, 20, 20). The median (3rd value) is 1616. Setting mean = median gives 68+x5=16    68+x=80    x=12\frac{68 + x}{5} = 16 \implies 68 + x = 80 \implies x = 12. Since 121612 \le 16, x=12x = 12 is valid.
The median of a 5-element set is the 3rd element when ordered.
3
Analyze Case 2 where 16x2016 \le x \le 20.
The sorted dataset is 12,16,x,20,2012, 16, x, 20, 20. The median is xx. Setting mean = median gives 68+x5=x    68+x=5x    4x=68    x=17\frac{68 + x}{5} = x \implies 68 + x = 5x \implies 4x = 68 \implies x = 17. Since 16172016 \le 17 \le 20, x=17x = 17 is valid.
When xx lies between 16 and 20, xx itself becomes the 3rd element of the ordered set.
4
Analyze Case 3 where x20x \ge 20.
The sorted dataset is 12,16,20,20,x12, 16, 20, 20, x. The median is 2020. Setting mean = median gives 68+x5=20    68+x=100    x=32\frac{68 + x}{5} = 20 \implies 68 + x = 100 \implies x = 32. Since 322032 \ge 20, x=32x = 32 is valid.
When x20x \ge 20, 20 is the 3rd element of the ordered set.

Anahtar Kavram

Solving for missing observations where mean equals median requires analyzing how the position of the variable affects the sorted order and the resulting median value.
Soru 124Soru

For all real numbers xx and yy, the custom operation \blacktriangle is defined by xy=2x2y2+xyx \blacktriangle y = 2x^2 - y^2 + xy. The function gg is defined for all real numbers nn by g(n)=n3g(n) = n \blacktriangle 3. If kk is a positive constant such that g(k)=0g(k) = 0, what is the value of kk?

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Cevap: 32\frac{3}{2}

Cevap

32\frac{3}{2}
Evaluating g(k)=k3g(k) = k \blacktriangle 3 using the rule xy=2x2y2+xyx \blacktriangle y = 2x^2 - y^2 + xy gives 2k232+3k=2k2+3k92k^2 - 3^2 + 3k = 2k^2 + 3k - 9. Setting this quadratic equal to zero gives (2k3)(k+3)=0(2k - 3)(k + 3) = 0. The roots are k=32k = \frac{3}{2} and k=3k = -3. Because kk is specified to be positive, the only valid solution is 32\frac{3}{2}.

Adım Adım Çözüm

1
Apply the definition of the custom operation \blacktriangle to evaluate g(k)g(k).
g(k)=k3=2(k)2(3)2+k(3)=2k29+3k=2k2+3k9g(k) = k \blacktriangle 3 = 2(k)^2 - (3)^2 + k(3) = 2k^2 - 9 + 3k = 2k^2 + 3k - 9
Substitute x=kx = k and y=3y = 3 into the given expression xy=2x2y2+xyx \blacktriangle y = 2x^2 - y^2 + xy.
2
Set the expression for g(k)g(k) equal to 00 and factor the quadratic equation.
2k2+3k9=(2k3)(k+3)=02k^2 + 3k - 9 = (2k - 3)(k + 3) = 0
We need to find values of kk for which g(k)=0g(k) = 0.
3
Solve for kk and apply the constraint that kk is a positive constant.
2k3=0    k=322k - 3 = 0 \implies k = \frac{3}{2} or k+3=0    k=3k + 3 = 0 \implies k = -3. Since k>0k > 0, k=32k = \frac{3}{2}.
Disregard the negative root k=3k = -3 because the problem specifies that kk must be positive.

Anahtar Kavram

Combining custom symbol operations with function notation to solve quadratic equations
Tahmini Süre:1m 30s
Soru 125Soru

In regular octagon ABCDEFGHABCDEFGH with side length 22, diagonals ADAD and BEBE intersect at point PP. What is the area of quadrilateral ABCPABCP?

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Cevap: 2+22 + \sqrt{2}

Cevap

2+22 + \sqrt{2}
In regular octagon ABCDEFGHABCDEFGH, each interior angle measures 135135^\circ. Segment ABCDABCD forms an isosceles trapezoid where ADAD is parallel to BCBC. The perpendicular distance from ADAD to BCBC is 2sin(45)=22 \sin(45^\circ) = \sqrt{2}, and AD=2+2(2cos(45))=2+22AD = 2 + 2(2 \cos(45^\circ)) = 2 + 2\sqrt{2}. Diagonal BEBE is parallel to side CDCD, so CBE=45\angle CBE = 45^\circ, which implies ABE=13545=90\angle ABE = 135^\circ - 45^\circ = 90^\circ. Triangle ABP\triangle ABP is therefore a right isosceles triangle with legs AB=2AB = 2 and BP=2BP = 2, yielding hypotenuse AP=22AP = 2\sqrt{2}. Quadrilateral ABCPABCP is a trapezoid with parallel sides BC=2BC = 2 and AP=22AP = 2\sqrt{2} and height h=2h = \sqrt{2}. Its area is 2+222×2=2+2\frac{2 + 2\sqrt{2}}{2} \times \sqrt{2} = 2 + \sqrt{2}.

Adım Adım Çözüm

1
Calculate the interior angle of a regular octagon
Interior angle = (82)×1808=135\frac{(8-2) \times 180^\circ}{8} = 135^\circ
Regular polygon interior angle formula.
2
Determine the orientation and length of diagonal ADAD
ADBCAD \parallel BC, height between them is h=2sin(45)=2h = 2 \sin(45^\circ) = \sqrt{2}, and base AD=2+2(2cos(45))=2+22AD = 2 + 2(2 \cos(45^\circ)) = 2 + 2\sqrt{2}
Quadrilateral ABCDABCD forms an isosceles trapezoid with side length 22 and interior angles 135135^\circ.
3
Determine the direction of diagonal BEBE and find intersection point PP
CBE=180135=45\angle CBE = 180^\circ - 135^\circ = 45^\circ, making ABE=13545=90\angle ABE = 135^\circ - 45^\circ = 90^\circ
Quadrilateral BCDEBCDE is an isosceles trapezoid with BECDBE \parallel CD.
4
Calculate the dimensions of right triangle ABP\triangle ABP and segment APAP
ABP\triangle ABP is a right triangle at BB with BAP=45\angle BAP = 45^\circ, AB=2AB = 2, BP=2BP = 2, and hypotenuse AP=22AP = 2\sqrt{2}
Since APBCAP \parallel BC, alternate interior angle relationships yield BAP=45\angle BAP = 45^\circ.
5
Calculate the area of quadrilateral ABCPABCP
Area(ABCP)=BC+AP2×h=2+222×2=(1+2)2=2+2\text{Area}(ABCP) = \frac{BC + AP}{2} \times h = \frac{2 + 2\sqrt{2}}{2} \times \sqrt{2} = (1 + \sqrt{2})\sqrt{2} = 2 + \sqrt{2}
Quadrilateral ABCPABCP is a trapezoid with parallel bases BC=2BC = 2 and AP=22AP = 2\sqrt{2} and height 2\sqrt{2}.

Anahtar Kavram

Properties of regular polygons, isosceles trapezoids, diagonal angles, and area decomposition.
Tahmini Süre:2m 30s
Soru 126Soru

A quality control department recorded the processing time, in days, for a batch of requests. The table below displays the frequency distribution of the processing times:

Processing Time (Days)Number of Requests
15
28
3kk
46
54

If kk is a positive integer and the median processing time for all requests in the batch is equal to 3 days, what is the minimum possible value of kk?

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Cevap: 4

Cevap

4
The correct answer is 4. There are 5+8=135 + 8 = 13 values less than 33. For 33 to be the median of the dataset, the median position must be greater than 1313. With k=4k = 4, the total number of items is N=23+4=27N = 23 + 4 = 27. For an odd dataset of size 2727, the median is the 27+12=14\frac{27 + 1}{2} = 14 th item. Since the first 1313 items are less than 33, the 1414 th item is 33, making 33 the median. Any value of k3k \le 3 results in a median less than 33.

Adım Adım Çözüm

1
Calculate the cumulative frequency of values below 3 days.
Number of requests with processing times of 1 or 2 days is 5+8=135 + 8 = 13.
To determine the median position, we first count how many data points lie strictly below 3 days.
2
Express the total number of requests NN in terms of kk.
N=5+8+k+6+4=23+kN = 5 + 8 + k + 6 + 4 = 23 + k.
The total number of requests determines whether NN is odd or even and where the median position lies.
3
Determine the condition for 3 days to be the median.
For 3 days to be the median, the median position must be greater than 13 so that it falls into the category of 3 days.
Since 13 values are strictly less than 3, the median rank must be at least 14.
4
Test minimum integer values for kk.
If k=3k = 3, N=26N = 26. The median is the average of the 1313 th value (22) and the 1414 th value (33), which is 2.52.5. If k=4k = 4, N=27N = 27. The median is the 1414 th value, which is 33.
Testing k=4k = 4 yields N=27N = 27 where the 1414 th value is 33, satisfying the median requirement.

Anahtar Kavram

Median of a Frequency Distribution Table
Tahmini Süre:1m 30s
Soru 127Soru

For all non-zero real numbers xx, the function ff satisfies the equation f(x)+2f(1x)=3xf(x) + 2f\left(\frac{1}{x}\right) = 3x. What is the value of f(2)f(2)?

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Cevap: 1-1

Cevap

1-1
Evaluating the functional equation at x=2x = 2 gives f(2)+2f(1/2)=6f(2) + 2f(1/2) = 6. Evaluating the equation at x=1/2x = 1/2 gives f(1/2)+2f(2)=3/2f(1/2) + 2f(2) = 3/2. Substituting f(1/2)=3/22f(2)f(1/2) = 3/2 - 2f(2) into the first equation produces 3f(2)+3=6-3f(2) + 3 = 6, which simplifies to f(2)=1f(2) = -1.

Adım Adım Çözüm

1
Substitute x=2x = 2 into the given functional equation f(x)+2f(1x)=3xf(x) + 2f\left(\frac{1}{x}\right) = 3x.
f(2)+2f(12)=6f(2) + 2f\left(\frac{1}{2}\right) = 6
This establishes a relation between the target value f(2)f(2) and the auxiliary value f(12)f\left(\frac{1}{2}\right).
2
Substitute x=12x = \frac{1}{2} into the original equation f(x)+2f(1x)=3xf(x) + 2f\left(\frac{1}{x}\right) = 3x.
f(12)+2f(2)=3(12)=32f\left(\frac{1}{2}\right) + 2f(2) = 3\left(\frac{1}{2}\right) = \frac{3}{2}
This provides a second independent linear equation relating f(2)f(2) and f(12)f\left(\frac{1}{2}\right).
3
Isolate f(12)f\left(\frac{1}{2}\right) in the second equation: f(12)=322f(2)f\left(\frac{1}{2}\right) = \frac{3}{2} - 2f(2), and substitute this expression into the first equation.
f(2)+2(322f(2))=6    f(2)+34f(2)=6    3f(2)+3=6f(2) + 2\left(\frac{3}{2} - 2f(2)\right) = 6 \implies f(2) + 3 - 4f(2) = 6 \implies -3f(2) + 3 = 6
Eliminating f(12)f\left(\frac{1}{2}\right) converts the system into a single linear equation in terms of f(2)f(2).
4
Solve 3f(2)+3=6-3f(2) + 3 = 6 for f(2)f(2).
3f(2)=3    f(2)=1-3f(2) = 3 \implies f(2) = -1
Subtracting 33 from both sides gives 3f(2)=3-3f(2) = 3, and dividing by 3-3 yields f(2)=1f(2) = -1.

Anahtar Kavram

Solving Functional Equations via Variable Substitution

Alternatif Yöntem

Generalize f(x)f(x) by setting f(x)=Ax+Bxf(x) = Ax + \frac{B}{x}. Substituting into f(x)+2f(1/x)=3xf(x) + 2f(1/x) = 3x gives (Ax+B/x)+2(A/x+Bx)=(A+2B)x+(2A+B)/x=3x(Ax + B/x) + 2(A/x + Bx) = (A + 2B)x + (2A + B)/x = 3x. Equating coefficients: A+2B=3A + 2B = 3 and 2A+B=0    B=2A    A4A=3    A=1,B=22A + B = 0 \implies B = -2A \implies A - 4A = 3 \implies A = -1, B = 2. Thus f(x)=x+2/xf(x) = -x + 2/x, so f(2)=2+2/2=1f(2) = -2 + 2/2 = -1.
Tahmini Süre:1m 30s
Soru 128Soru

A food processing plant packages grain using two automated lines, Line A and Line B. Line A operates at a constant rate of 4040 bags per minute, and Line B operates at a constant rate of 6060 bags per minute. Line A begins filling a batch of 4,2004,200 bags alone. After 1515 minutes, Line A's rate decreases by 25%25\%, and Line B is turned on to work alongside Line A until the batch is complete. How many total minutes does Line A operate to complete the batch?

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Cevap: 55 minutes

Cevap

55 minutes
In the first 15 minutes, Line A fills 40×15=60040 \times 15 = 600 bags, leaving 4,200600=3,6004,200 - 600 = 3,600 bags remaining. Line A's rate then drops to 40×0.75=3040 \times 0.75 = 30 bags per minute. Working together with Line B (6060 bags per minute), their combined rate is 30+60=9030 + 60 = 90 bags per minute. Filling the remaining 3,6003,600 bags takes 3,60090=40\frac{3,600}{90} = 40 minutes. Thus, Line A operates for a total of 15+40=5515 + 40 = 55 minutes.

Adım Adım Çözüm

1
Calculate the number of bags filled by Line A during the first 15 minutes.
Line A filled 40 bags/min×15 min=600 bags40 \text{ bags/min} \times 15 \text{ min} = 600 \text{ bags}.
Line A worked alone for 15 minutes at its initial constant rate.
2
Determine the remaining number of bags to be filled.
Remaining bags = 4,200600=3,600 bags4,200 - 600 = 3,600 \text{ bags}.
Subtract the bags already completed from the total batch size.
3
Calculate Line A's reduced rate and the new combined rate of both lines.
Line A's new rate = 40×(10.25)=30 bags/min40 \times (1 - 0.25) = 30 \text{ bags/min}. Combined rate = 30+60=90 bags/min30 + 60 = 90 \text{ bags/min}.
Line A's filling rate drops by 25%, and Line B contributes 60 bags per minute simultaneously.
4
Calculate the time needed for both lines to finish the remaining bags.
Time for second phase = 3,600 bags90 bags/min=40 minutes\frac{3,600 \text{ bags}}{90 \text{ bags/min}} = 40 \text{ minutes}.
Divide remaining work by the combined filling rate.
5
Calculate the total time Line A was operating.
Total operating time = 15 min+40 min=55 minutes15 \text{ min} + 40 \text{ min} = 55 \text{ minutes}.
Line A operated during both the initial 15-minute period and the subsequent 40-minute period.

Anahtar Kavram

Linear Modeling and Piecewise Work-Rate Scenarios
Tahmini Süre:2m 0s
Soru 129Soru

For all real numbers aa and bb such that b0b \neq 0 and aba \neq -b, which of the following expressions is equivalent to a3bab3a2b+2ab2+b3\frac{a^3b - ab^3}{a^2b + 2ab^2 + b^3}?

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Cevap: a(ab)a+b\frac{a(a - b)}{a + b}

Cevap

a(ab)a+b\frac{a(a - b)}{a + b}
Factoring the numerator yields ab(a2b2)=ab(ab)(a+b)ab(a^2 - b^2) = ab(a - b)(a + b), and factoring the denominator yields b(a2+2ab+b2)=b(a+b)2b(a^2 + 2ab + b^2) = b(a + b)^2. Dividing both the numerator and the denominator by the common factor b(a+b)b(a + b) produces a(ab)a+b\frac{a(a - b)}{a + b}.

Adım Adım Çözüm

1
Factor out the greatest common monomial factor from the numerator and denominator.
The numerator a3bab3a^3b - ab^3 becomes ab(a2b2)ab(a^2 - b^2), and the denominator a2b+2ab2+b3a^2b + 2ab^2 + b^3 becomes b(a2+2ab+b2)b(a^2 + 2ab + b^2).
Extracting common terms simplifies polynomials prior to applying polynomial identities.
2
Apply polynomial algebraic identities to factor the remaining terms.
a2b2=(ab)(a+b)a^2 - b^2 = (a - b)(a + b) and a2+2ab+b2=(a+b)2a^2 + 2ab + b^2 = (a + b)^2. Thus, the expression becomes ab(ab)(a+b)b(a+b)2\frac{ab(a - b)(a + b)}{b(a + b)^2}.
The difference of squares and perfect square trinomial identities allow complete factorization.
3
Cancel non-zero common factors from the numerator and denominator.
Canceling bb and one factor of (a+b)(a + b) leaves a(ab)a+b\frac{a(a - b)}{a + b}.
Dividing both numerator and denominator by b(a+b)b(a + b) yields the simplified expression.

Anahtar Kavram

Simplifying rational expressions using common monomial factoring, difference of squares, and perfect square trinomial identities.
Tahmini Süre:1m 30s
Soru 130Soru

If xx is a real number that satisfies the equation (x3)2=16(x - 3)^2 = 16, which of the following could be the value of x24xx^2 - 4x? Select all such values.

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Cevap: 55; 2121

Cevap

The possible values of x24xx^2 - 4x are 55 and 2121.
Taking the square root of both sides of (x3)2=16(x - 3)^2 = 16 yields x3=±4x - 3 = \pm 4. This gives two solutions for xx: x=7x = 7 and x=1x = -1. Substituting x=7x = 7 into x24xx^2 - 4x gives 4928=2149 - 28 = 21. Substituting x=1x = -1 into x24xx^2 - 4x gives (1)24(1)=1+4=5(-1)^2 - 4(-1) = 1 + 4 = 5. Thus, both 55 and 2121 are valid values.

Adım Adım Çözüm

1
Solve the quadratic equation for xx
x3=4    x=7x - 3 = 4 \implies x = 7 or x3=4    x=1x - 3 = -4 \implies x = -1
Taking the square root of both sides of (x3)2=16(x - 3)^2 = 16 yields both positive and negative roots.
2
Substitute the first root into the expression x24xx^2 - 4x
724(7)=4928=217^2 - 4(7) = 49 - 28 = 21
Evaluating the target expression for x=7x = 7.
3
Substitute the second root into the expression x24xx^2 - 4x
(1)24(1)=1+4=5(-1)^2 - 4(-1) = 1 + 4 = 5
Evaluating the target expression for x=1x = -1.

Anahtar Kavram

Quadratic Equations and Factoring
Soru 131Soru

If xx is a real number such that (x24)23(x24)10=0(x^2 - 4)^2 - 3(x^2 - 4) - 10 = 0, which of the following could be the value of xx? Select all such values.

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Cevap: 3-3; 2-\sqrt{2}; 33

Cevap

The values that satisfy the equation are 3-3, 2-\sqrt{2}, and 33.
The given equation is in quadratic form with respect to (x24)(x^2 - 4). Letting u=x24u = x^2 - 4, we factor the equation as (u5)(u+2)=0(u - 5)(u + 2) = 0, giving u=5u = 5 or u=2u = -2. Setting x24=5x^2 - 4 = 5 gives x2=9x^2 = 9, which yields x=3x = 3 or x=3x = -3. Setting x24=2x^2 - 4 = -2 gives x2=2x^2 = 2, which yields x=2x = \sqrt{2} or x=2x = -\sqrt{2}. Thus, 3-3, 2-\sqrt{2}, and 33 are all valid solutions.

Adım Adım Çözüm

1
Use algebraic substitution to simplify the quadratic form.
Let u=x24u = x^2 - 4. The equation becomes u23u10=0u^2 - 3u - 10 = 0.
Recognizing the structure as a quadratic equation in terms of (x24)(x^2 - 4) simplifies factoring.
2
Factor the quadratic equation in terms of uu.
(u5)(u+2)=0(u - 5)(u + 2) = 0, giving solutions u=5u = 5 or u=2u = -2.
Finding the roots of the substituted variable uu leads to the possible values for x24x^2 - 4.
3
Substitute back x24x^2 - 4 for uu and solve for xx in each case.
For u=5u = 5: x24=5    x2=9    x=3x^2 - 4 = 5 \implies x^2 = 9 \implies x = 3 or x=3x = -3.
For u=2u = -2: x24=2    x2=2    x=2x^2 - 4 = -2 \implies x^2 = 2 \implies x = \sqrt{2} or x=2x = -\sqrt{2}.
Taking both positive and negative square roots provides all valid real solutions.

Anahtar Kavram

Quadratic Form Substitution and Factoring
Tahmini Süre:1m 40s
Soru 132Soru

If xx is a negative real number such that (x+5)2=36(x + 5)^2 = 36, what is the value of x22xx^2 - 2x?

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Cevap: 143143

Cevap

The value of x22xx^2 - 2x is 143143.
Taking the square root of both sides of (x+5)2=36(x + 5)^2 = 36 gives x+5=6x + 5 = 6 or x+5=6x + 5 = -6. Solving for xx yields x=1x = 1 or x=11x = -11. Because xx is given as a negative real number, x=11x = -11. Evaluating the target expression at x=11x = -11 yields (11)22(11)=121+22=143(-11)^2 - 2(-11) = 121 + 22 = 143.

Adım Adım Çözüm

1
Solve the quadratic equation for xx by applying the square root property.
x+5=±36=±6x + 5 = \pm \sqrt{36} = \pm 6
Taking the square root of both sides yields both positive and negative root options.
2
Determine the two potential solutions for xx.
x=65=1x = 6 - 5 = 1 or x=65=11x = -6 - 5 = -11
Isolating xx gives two real solutions.
3
Select the valid solution based on the problem constraints.
x=11x = -11
The stem specifies that xx must be a negative real number, so x=1x = 1 is rejected.
4
Substitute x=11x = -11 into the expression x22xx^2 - 2x.
(11)22(11)=121+22=143(-11)^2 - 2(-11) = 121 + 22 = 143
Squaring a negative number yields a positive result, and subtracting a negative quantity adds to the total.

Anahtar Kavram

Solving quadratic equations using square roots and evaluating algebraic expressions
Soru 133Soru

Consider the following GRE Issue prompt claim:

"To foster true innovation in scientific research, government funding bodies should allocate financial resources exclusively to unconstrained, curiosity-driven inquiry rather than targeted, application-oriented projects."

An essay writer aims to deconstruct this prompt by identifying its primary unstated assumption to form a critical foundation for their thesis. Which of the following best identifies the essential unstated assumption that underlies the prompt's central recommendation?

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Cevap: Targeted, application-oriented projects rely entirely on existing scientific paradigms and are inherently incapable of yielding foundational breakthroughs that redefine a field.

Cevap

The essential unstated assumption is that targeted, application-oriented projects rely entirely on existing paradigms and are inherently incapable of yielding foundational breakthroughs that redefine a field.
The prompt advocates an absolute policy rule: funding must go exclusively to curiosity-driven research in order to foster true innovation. For this recommendation to hold logically, one must assume that application-oriented research is fundamentally incapable of producing true innovation. If applied research could lead to fundamental breakthroughs, the prompt's recommendation for total exclusivity would crumble. Therefore, identifying that targeted research is assumed to be incapable of foundational breakthroughs directly uncovers the prompt's central unstated premise.

Adım Adım Çözüm

1
Analyze the prompt's core claim and recommendation structure.
The prompt claims that fostering 'true innovation' requires exclusive funding for 'curiosity-driven inquiry' over 'application-oriented projects.'
Deconstructing an Issue prompt requires isolating the prescriptive assertion and its scope.
2
Identify the logical bridge required to justify the absolute exclusion of applied research.
To justify excluding application-oriented research completely in pursuit of true innovation, the arguer must assume that application-oriented research contributes zero or negligible true innovation.
If applied research could also produce true innovation, exclusive funding of curiosity-driven research would not be logically necessary.
3
Evaluate the option choices to select the statement representing this fundamental presupposition.
The statement asserting that application-oriented projects are inherently incapable of yielding foundational breakthroughs directly exposes this underlying premise.
Exposing this hidden assumption provides the essay writer with the strongest leverage to construct a nuanced counterargument.

Anahtar Kavram

Deconstructing Issue Prompts via Underlying Assumptions
Soru 134Soru

Paleoclimatologists analyzing speleothem oxygen isotope ratios from subterranean caves in the Amazon basin have posited that a prolonged megadrought precipitated the collapse of pre-Columbian urban settlements around 1350 CE. Proponents of this climate-deterministic model point to a sharp, synchronous elevation in δ18O\delta^{18}\text{O} signatures across multiple cave sites as unequivocal evidence of widespread precipitation failure. However, recent high-resolution palynological evidence from adjacent lacustrine sediment cores reveals that agricultural cultivation and forest clearing continued unabated throughout the purported drought interval. This persistence of intensive land use strongly suggests that indigenous socio-ecological systems possessed sufficient hydrologic resilience to buffer against regional rainfall deficits. Consequently, attributing the abandonment of these complex settlements primarily to exogenous climatic forcing oversimplifies the intricate interplay between anthropogenic environmental modification and institutional governance.

Which sentence in the passage presents empirical evidence that directly counters the climate-deterministic explanation for the settlement collapse?

Cevabı ve açıklamayı göster

Cevap: Sentence 3; 3; the third sentence; However, recent high-resolution palynological evidence from adjacent lacustrine sediment cores reveals that agricultural cultivation and forest clearing continued unabated throughout the purported drought interval.

Cevap

The third sentence ('However, recent high-resolution palynological evidence from adjacent lacustrine sediment cores reveals that agricultural cultivation and forest clearing continued unabated throughout the purported drought interval.') provides the empirical counterevidence.
The sentence stating that high-resolution palynological evidence reveals uninterrupted agricultural cultivation during the purported drought provides concrete physical data that directly challenges the premise that climate deterioration forced the abandonment of the settlements.

Adım Adım Çözüm

1
Identify the central claim of the climate-deterministic model.
The main claim (introduced in Sentence 1 and supported in Sentence 2) is that a severe megadrought caused the collapse of pre-Columbian urban settlements.
Understanding the target hypothesis is essential before searching for empirical evidence that weakens or refutes it.
2
Scan the passage for empirical data that contradicts this claim.
Sentence 3 introduces fossil pollen (palynological) data showing uninterrupted agricultural activity and land modification during the exact period of the alleged drought.
Continued farming directly challenges the assertion that environmental conditions collapsed societal infrastructure.
3
Distinguish empirical findings from subsequent interpretations or conclusions.
Sentence 3 contains the actual physical data (palynological core evidence), whereas Sentence 4 and Sentence 5 present logical inferences and overall conclusions drawn from that evidence.
The prompt specifically asks for the sentence presenting empirical evidence rather than the author's synthesis or conclusion.

Anahtar Kavram

Identifying empirical counterevidence within Reading Comprehension argument structures
Soru 135Soru

A municipal power authority introduced automated smart meters across residential districts to detect voltage anomalies and isolate localized power outages automatically. During the six months following installation, the total duration of power outages experienced by residents in these districts decreased by 35 percent compared to the same period in previous years. Municipal officials concluded that the automatic anomaly detection of the smart meters was directly responsible for reducing outage durations.

Which of the following, if true, provides the strongest support for the municipal officials' conclusion?

Cevabı ve açıklamayı göster

Cevap: During the six-month period following installation, the region experienced weather patterns and storm frequencies typical of previous years.

Cevap

The argument is most strengthened by the statement showing that weather patterns and storm frequencies during the post-installation period were typical of previous years.
The conclusion attributes the 35 percent drop in outage durations directly to the smart meters' anomaly detection capability. The statement confirming that storm frequencies and weather patterns were typical of prior years eliminates an alternative explanation—namely, that a period of unusually mild weather reduced grid damage and caused the drop in outage times. By ruling out this key alternative cause, the statement significantly strengthens the causal connection proposed by municipal officials.

Adım Adım Çözüm

1
Identify the premise and conclusion of the argument
Premise: Outage durations dropped 35 percent after installing automated smart meters. Conclusion: Smart meter anomaly detection directly caused the reduction.
Understanding the precise causal claim is essential for evaluating statements that strengthen or weaken it.
2
Identify potential logical vulnerabilities in the causal claim
The main vulnerability is that an external factor (such as unusually mild weather or grid infrastructure repairs) might be the true cause of the reduced outage durations.
A standard way to strengthen a causal conclusion is to eliminate competing alternative causes.
3
Evaluate the options for a statement that addresses these vulnerabilities
The option noting that weather conditions were typical of previous years confirms that mild weather was not responsible for the decrease, thereby supporting the smart meters as the true cause.
Ruling out a plausible confounding variable increases the probability that the author's stated cause is correct.

Anahtar Kavram

Strengthening Causal Claims by Ruling Out Alternative Causes
Soru 136Soru

Read the passage below:

Conventional economic models long assumed that consumer decisions are driven entirely by rational utility maximization. However, recent empirical work in behavioral economics demonstrates that cognitive biases systematically alter financial choices. For instance, a 2018 study observed that individuals consistently value immediate rewards over significantly larger delayed gains, a phenomenon known as hyperbolic discounting. Critics contend that such laboratory findings fail to account for real-world market mechanisms that attenuate irrational behavior. Nonetheless, these findings have prompted policymakers to redesign default savings plans to nudge individuals toward optimal long-term outcomes.

Which sentence in the passage provides specific empirical evidence supporting the claim that cognitive biases influence financial decision-making?

Cevabı ve açıklamayı göster

Cevap: For instance, a 2018 study observed that individuals consistently value immediate rewards over significantly larger delayed gains, a phenomenon known as hyperbolic discounting.

Cevap

The sentence stating, 'For instance, a 2018 study observed that individuals consistently value immediate rewards over significantly larger delayed gains, a phenomenon known as hyperbolic discounting.'
The sentence referencing the 2018 study directly provides specific empirical evidence by citing observational data on hyperbolic discounting to demonstrate how cognitive biases affect financial choices.

Adım Adım Çözüm

1
Analyze the prompt requirement
The prompt requires selecting a sentence that supplies specific empirical evidence (data, study, or observed phenomenon) rather than a theoretical assertion or policy outcome.
Select-in-passage questions require identifying the exact sentence fulfilling a specific rhetorical function.
2
Evaluate the rhetorical role of each sentence in the passage
The sentence referencing the 2018 study introduces specific experimental observation ('hyperbolic discounting') supporting the broader claim.
Concrete study details serve as empirical evidence for general theoretical claims.

Anahtar Kavram

Select-in-Passage Question Analysis: Identifying Supporting Empirical Evidence
Soru 137Soru

Based on the passage below, what structural role does the detail regarding third-party debt assignments play in Vance's overall argument? Complete the following statement with an appropriate functional verb:

The reference to legally enforceable third-party debt assignments serves to {{blank_1}} the objection that Flemish manorial ledgers were merely informal administrative record-keeping systems rather than genuine financial instruments.

Aşağıdaki boşlukları doldurun

For decades, economic historians attributing the rise of early modern European banking institutions primarily to Mediterranean commercial networks treated Northern European agrarian arrangements as largely static background conditions. However, recent reassessments of medieval manor accounting led by Dr. Evelyn Vance suggest that institutional credit instruments were independently synthesized in lowland agrarian estates long before Mediterranean techniques proliferated northward. Vance points out that non-monetized credit ledgers in fourteenth-century Flemish manors performed functionally equivalent clearinghouse operations, settling seasonal debt obligations without specie transfers. Critics of Vance's thesis contend that these estate ledgers were merely informal administrative record-keeping systems lacking negotiable instruments, thus failing to constitute true financial intermediation. To substantiate her position against these detractors, Vance emphasizes that the Flemish ledgers permitted third-party debt assignments that were legally enforceable in local manorial courts. Ultimately, while Vance does not argue that rural manors possessed fully developed capital markets, her evidence demonstrates that key functional components of modern banking emerged autonomously in agrarian contexts.

Sentence to complete:
The reference to legally enforceable third-party debt assignments serves to
the objection that Flemish manorial ledgers were merely informal administrative record-keeping systems rather than genuine financial instruments.
Cevabı ve açıklamayı göster

Cevap

rebut (or counter / refute / undermine / challenge)
The sentence citing legally enforceable third-party debt assignments directly follows the critics' argument that Flemish ledgers lacked negotiability. By providing empirical evidence of negotiability and legal enforcement, the detail serves rhetorically to rebut, counter, or refute the critics' objection, defending Vance's central position.

Adım Adım Çözüm

1
Analyze the structural flow and argumentative trajectory of the passage.
The text moves from a traditional scholarly view to Vance's revisionist thesis, followed by an objection from critics, Vance's counter-evidence, and finally a qualified broader conclusion.
Understanding the contextual placement of each claim helps determine how individual sentences function relative to surrounding counterarguments.
2
Examine the specific relationship between the critics' objection and the highlighted detail.
The critics claim the ledgers lacked negotiable instruments and were thus not true financial intermediation. Vance responds by introducing third-party debt assignments, showing legal negotiability existed.
Offering empirical facts that directly contradict a criticism functions rhetorically as a rebuttal or refutation of that objection.
3
Select a precise functional verb that captures this rhetorical role.
Verbs such as 'rebut', 'refute', 'counter', or 'undermine' precisely describe introducing evidence to dismantle a opposing counterargument.
These verbs denote active refutation within academic discourse.

Anahtar Kavram

Rhetorical Role of Evidence in Rebutting Counterarguments
Tahmini Süre:2m 30s
Soru 138Soru

Recent investigations into urban microclimates have challenged the long-standing assumption that city green spaces act uniformly as cooling zones. While expansive municipal parks undeniably reduce ambient temperatures through evapotranspiration, smaller pockets of vegetation—such as roadside bioswales and residential gardens—exhibit far more variable thermal effects. Microclimate researchers demonstrate that the cooling efficacy of small-scale urban greenery is contingent upon canopy density, soil moisture retention, and local wind corridors. In densely built environments with high-rise structures, sparse vegetation can occasionally trap heat by reducing surface air movement without offering sufficient shade. Consequently, urban planners are urged to move beyond aggregate metric goals for total green coverage and instead adopt site-specific spatial strategies to optimize thermal relief.

Based on the passage, which of the following statements correctly capture a main idea or primary purpose of the author? Select all options that apply.

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Cevabı ve açıklamayı göster

Cevap: Arguing that the thermal mitigation benefits of urban greenery depend on specific contextual factors rather than uniform presence alone.; Urging urban planners to transition from broad coverage targets to tailored, site-specific vegetation strategies.

Cevap

The passage primarily aims to demonstrate that urban greenery's cooling effects depend on local environmental conditions and to recommend site-specific planning over aggregate coverage goals.
The passage centers on showing that cooling benefits from small-scale urban greenery depend heavily on structural and environmental context (such as canopy density and wind corridors) rather than just presence, and concludes by urging urban planners to adopt site-specific strategies rather than relying on aggregate green space targets. Thus, both statements reflecting these two points accurately capture the main idea and primary purpose.

Adım Adım Çözüm

1
Identify the primary claim and scope of the passage.
The author contrasts the uniform cooling assumption of large parks with the variable effectiveness of small vegetation pockets, establishing that efficacy depends on local context.
Establishing the core argument requires synthesizing the main topic across the passage.
2
Identify the author's primary recommendation.
The final sentence explicitly advises urban planners to shift from aggregate metrics to site-specific strategies.
The conclusion explicitly states the practical purpose toward which the rest of the text builds.
3
Evaluate the choices against the identified main idea and primary purpose.
The statements highlighting contextual dependence and the recommendation for tailored urban planning accurately express the main ideas of the text.
Correct options must align with the passage's overall argument without overstating claims or focusing on peripheral details.

Anahtar Kavram

Main Idea and Primary Purpose
Soru 139Soru

Consider the following draft body paragraph from an essay responding to a GRE Issue prompt on municipal governance:

"Municipalities should prioritize reserving vacant downtown lots for public parks rather than selling them for commercial development. Opponents might argue that commercial developments generate immediate property tax revenues necessary to fund municipal services. However, this perspective overlooks the fact that public parks increase neighboring property values over time, thereby indirectly expanding the tax base while simultaneously improving community health."

Which of the following statements accurately describe the structural integration of the counterargument and rebuttal in this excerpt? (Select all that apply.)

Geçerli olan tümünü seçin

Cevabı ve açıklamayı göster

Cevap: The paragraph introduces an opposing perspective using a clear transition to distinguish the counterargument from the author's primary position.; The rebuttal directly responds to the central premise of the counterargument by offering an alternative economic reasoning.

Cevap

The statements recognizing the clear transitional introduction of the opposing perspective and the direct economic engagement of the rebuttal are both correct.
The paragraph successfully integrates the counterargument by first signaling it with clear transitional phrasing ('Opponents might argue that...') and then directly countering its economic premise regarding tax revenues with a logical counter-explanation ('public parks increase neighboring property values over time, thereby indirectly expanding the tax base').

Adım Adım Çözüm

1
Analyze how the counterargument is introduced within the paragraph structure.
The author uses 'Opponents might argue that...' to explicitly signal a shift from the main claim to an opposing viewpoint.
Clear transitional framing ensures the reader distinguishes between the author's core thesis and alternative perspectives.
2
Evaluate the structural and logical connection between the counterargument and the rebuttal.
The author transitions with 'However' and refutes the tax revenue concern by demonstrating an alternative, long-term economic mechanism (property value appreciation).
An effective rebuttal must engage directly with the premise of the counterargument rather than shifting to an unrelated topic.

Anahtar Kavram

Effective structural integration requires clear transitional signaling of opposing claims followed by a direct, logically aligned rebuttal.
Soru 140Soru

Consider the following GRE Issue prompt and analytical task:

Prompt: "As artificial intelligence and automated systems become increasingly integrated into public governance, society must prioritize efficiency over human oversight in municipal decision-making."

Task: Write a response in which you discuss the extent to which you agree or disagree with the claim. In developing and supporting your position, address the specific scope and operational definitions of key concepts central to the claim.

Which of the following thesis statements best operationalizes key terms and establishes an effective scope for an essay responding to this prompt?

Cevabı ve açıklamayı göster

Cevap: While automated systems streamline routine administrative procedures such as transit scheduling, human oversight remains indispensable when algorithms impact civil liberties or welfare distribution, requiring 'efficiency' to be defined not merely as processing speed, but as equitable service delivery within specific governance domains.

Cevap

The statement that qualifies the role of automation by distinguishing routine administration from high-stakes civil rights decisions and redefines 'efficiency' as equitable service delivery.
The correct response effectively defines the key term 'efficiency' as equitable service delivery rather than mere speed, and establishes clear scope boundaries by contrasting routine municipal administration (where automation excels) with sensitive areas like civil liberties and welfare allocation (where human oversight is crucial). This directly satisfies the GRE AWA requirement for defining scope and operationalizing terms.

Adım Adım Çözüm

1
Analyze the prompt requirements for key term definition and scope establishment.
Identified the central concepts requiring definition ('efficiency', 'human oversight', 'municipal decision-making') and the need for qualifying scope boundaries.
Effective GRE Issue response framing requires defining ambiguous terms and delineating where the claim holds true versus where it breaks down.
2
Evaluate each candidate thesis against the prompt task instructions.
Distinguished between vague, absolutist, or one-sided statements and the statement that offers operational definitions and contextual boundaries.
A high-scoring GRE Issue thesis must avoid rigid dogmatism and vague summaries while establishing explicit criteria for evaluation.
3
Confirm the option that best fulfills both key term operationalization and scope setting.
Selected the thesis that defines 'efficiency' beyond speed and restricts automation to routine administrative contexts while reserving human oversight for high-stakes decisions.
This framing directly answers the task prompt by establishing clear domain limits and explicit operational definitions.

Anahtar Kavram

Defining Key Terms & Establishing Essay Scope
ÖncekiSayfa 7 / 107Sonraki
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