Tüm alıştırma soruları

2131 soru

Soru 1481Soru

A company allocates a total budget of $4,000\$4,000 between its marketing and research departments. The amount allocated to marketing is $400\$400 more than three times the amount allocated to research. How many dollars are allocated to research?

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Cevap: 900

Cevap

The amount allocated to research is 900900 dollars.
If xx represents the research budget, the marketing budget is 3x+4003x + 400. Summing both department allocations gives x+(3x+400)=4,000x + (3x + 400) = 4,000. Simplifying this linear equation gives 4x+400=4,0004x + 400 = 4,000, leading to 4x=3,6004x = 3,600 and x=900x = 900.

Adım Adım Çözüm

1
Define the unknown variable and express both allocations algebraically.
Let xx be the research budget. The marketing budget is 3x+4003x + 400.
The marketing allocation is defined relative to the research allocation.
2
Formulate a linear equation representing the combined budget.
x+(3x+400)=4000x + (3x + 400) = 4000
The total budget allocated across both departments is $4,000\$4,000.
3
Solve the linear equation for xx.
4x+400=4000    4x=3600    x=9004x + 400 = 4000 \implies 4x = 3600 \implies x = 900
Combine like terms, isolate the variable term by subtracting 400400, and divide by 44.

Anahtar Kavram

Setting up and solving a linear equation in one variable from a real-life word problem context.
Soru 1482Soru

In a circle centered at point OO, the ratio of the area of sector AOBAOB to the area of the entire circle is 3:83:8. If the total perimeter of sector AOBAOB is 24+9π24 + 9\pi, what is the radius of the circle?

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Cevap: 12

Cevap

The radius of the circle is 12.
Since the ratio of the sector area to the total circle area is 3:83:8, the sector accounts for 38\frac{3}{8} of the entire circumference 2πr2\pi r, making the arc length L=38(2πr)=34πrL = \frac{3}{8}(2\pi r) = \frac{3}{4}\pi r. The perimeter of the sector is 2r+L=2r+34πr2r + L = 2r + \frac{3}{4}\pi r. Equating this to 24+9π24 + 9\pi gives 2r=242r = 24, so r=12r = 12.

Adım Adım Çözüm

1
Relate sector area ratio to arc length
Arc length L=34πrL = \frac{3}{4}\pi r
The fraction of the circle occupied by the sector is 38\frac{3}{8}, so the arc length is 38\frac{3}{8} of the circle's circumference 2πr2\pi r.
2
Formulate the perimeter expression for sector AOBAOB
Perimeter = 2r+34πr2r + \frac{3}{4}\pi r
The boundary of a sector includes two straight radii of length rr plus the curved arc length LL.
3
Equate to given perimeter and solve for rr
r=12r = 12
Comparing 2r+34πr2r + \frac{3}{4}\pi r to 24+9π24 + 9\pi, setting 2r=242r = 24 yields r=12r = 12, which also satisfies 34π(12)=9π\frac{3}{4}\pi (12) = 9\pi.

Anahtar Kavram

Perimeter of a circle sector and fractional relationship between sector area, central angle, and arc length.
Soru 1483Soru
If xx is a positive real number satisfying the equation
x3xxx1/43=16\sqrt[3]{\frac{x^3 \sqrt{x\sqrt{x}}}{x^{-1/4}}} = 16
what is the value of xx?
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Cevap: 8

Cevap

8
By converting all radicals into fractional exponents and systematically applying exponent rules, the expression under the cube root simplifies to x4x^4. Taking the cube root gives x4/3=16x^{4/3} = 16. Solving for xx by raising both sides to 3/43/4 yields x=163/4=(24)3/4=23=8x = 16^{3/4} = (2^4)^{3/4} = 2^3 = 8.

Adım Adım Çözüm

1
Express the inner nested radical using fractional exponents
\sqrt{x\sqrt{x}} = \sqrt{x \cdot x^{1/2}} = \sqrt{x^{3/2}} = x^{3/4}
Applying the product and power rules of exponents: xaxb=xa+bx^a \cdot x^b = x^{a+b} and (xa)b=xab(x^a)^b = x^{ab}.
2
Simplify the numerator inside the outer radical
x^3 \cdot x^{3/4} = x^{3 + 3/4} = x^{15/4}
Multiplying exponential terms with the same base requires adding their exponents.
3
Divide by the negative exponent in the denominator
\frac{x^{15/4}}{x^{-1/4}} = x^{15/4 - (-1/4)} = x^{16/4} = x^4
Dividing exponential terms with the same base requires subtracting the denominator exponent from the numerator exponent.
4
Apply the outer cube root to the simplified expression
x43=(x4)1/3=x4/3\sqrt[3]{x^4} = (x^4)^{1/3} = x^{4/3}
The nn-th root of an expression is equivalent to raising that expression to the power of 1/n1/n.
5
Solve the resulting exponential equation for xx
x^{4/3} = 16 \implies x = 16^{3/4} = (2^4)^{3/4} = 2^3 = 8
Raise both sides of x4/3=16x^{4/3} = 16 to the power of 3/43/4 to isolate xx.

Anahtar Kavram

Simplifying nested algebraic radicals and solving equations with fractional exponents using exponent rules.
Soru 1484Soru

A bookstore sells hardcover books for $15\$15 each and paperback books for $10\$10 each. A customer purchased a total of 1212 books and spent $150\$150 in total. Let hh represent the number of hardcover books purchased and pp represent the number of paperback books purchased. Which of the following equations correctly model this situation? Select all such equations.

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Cevap: h+p=12h + p = 12; 15h+10p=15015h + 10p = 150; 3h+2p=303h + 2p = 30

Cevap

The correct equations are h+p=12h + p = 12, 15h+10p=15015h + 10p = 150, and 3h+2p=303h + 2p = 30.
The system of equations that models this situation requires one equation for the total count of books (h+p=12h + p = 12) and one for the total monetary expenditure (15h+10p=15015h + 10p = 150). Dividing the cost equation 15h+10p=15015h + 10p = 150 by 5 gives another mathematically equivalent relation 3h+2p=303h + 2p = 30. Thus, all three of these statements accurately represent the given conditions.

Adım Adım Çözüm

1
Formulate the total quantity equation
h+p=12h + p = 12
The total number of books bought is 12, which is the sum of hardcover books hh and paperback books pp.
2
Formulate the total cost equation
15h+10p=15015h + 10p = 150
Hardcover books cost $15\$15 each and paperbacks cost $10\$10 each, yielding a total cost of $150\$150.
3
Simplify the total cost equation by dividing by the greatest common divisor
3h+2p=303h + 2p = 30
Dividing all coefficients in 15h+10p=15015h + 10p = 150 by 55 produces an equivalent simplified linear equation.

Anahtar Kavram

Linear Modeling and Equivalent Equations
Tahmini Süre:1m 0s
Soru 1485Soru

In a geometric plane, line L1L_1 is parallel to line L2L_2. Points AA and CC lie on line L1L_1, and points BB and DD lie on line L2L_2. Line segments ABAB and CDCD intersect at point XX located between lines L1L_1 and L2L_2. If measure of XAC=42\angle XAC = 42^\circ and measure of XDB=35\angle XDB = 35^\circ, what is the measure, in degrees, of AXC\angle AXC?

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Cevap: 103

Cevap

The measure of AXC\angle AXC is 103103^\circ.
Line L1L_1 is parallel to line L2L_2, meaning segment ACAC is parallel to segment BDBD. Transversal line CDCD intersects both parallel lines, creating alternate interior angles XCA\angle XCA and XDB\angle XDB. Hence, XCA=XDB=35\angle XCA = \angle XDB = 35^\circ. Inside triangle ACXACX, the three interior angles must sum to 180180^\circ. Substituting the values yields AXC=180(42+35)=103\angle AXC = 180^\circ - (42^\circ + 35^\circ) = 103^\circ.

Adım Adım Çözüm

1
Identify parallel lines and the transversal line
Line segment CDCD acts as a transversal line intersecting parallel lines L1L_1 and L2L_2.
Points AA and CC lie on line L1L_1 while points BB and DD lie on line L2L_2 with L1L2L_1 \parallel L_2.
2
Apply the alternate interior angles theorem
\angle XCA = \angle XDB = 35^\circ
When a transversal intersects two parallel lines, alternate interior angles are equal.
3
Calculate the target angle using the sum of interior angles in a triangle
\angle AXC = 180^\circ - (42^\circ + 35^\circ) = 103^\circ
The sum of interior angles in triangle ACXACX is 180180^\circ.

Anahtar Kavram

Properties of parallel lines intersected by a transversal and the triangle angle sum theorem.
Soru 1486Soru

In the xyxy-plane, point PP has coordinates (3,4)(3, -4). Point PP is reflected across the yy-axis to form point QQ. Point QQ is then translated upward by 22 units to form point RR. Which of the following statements must be true? Select all that apply.

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Cevap: The coordinates of point QQ are (3,4)(-3, -4).; Point RR lies in Quadrant III.

Cevap

The correct statements are that the coordinates of point QQ are (3,4)(-3, -4) and that point RR lies in Quadrant III.
Reflecting (3,4)(3, -4) across the yy-axis yields (3,4)(-3, -4) for point QQ. Translating (3,4)(-3, -4) upward by 22 units gives (3,2)(-3, -2) for point RR. Because both coordinates of RR are negative, it resides in Quadrant III.

Adım Adım Çözüm

1
Perform the reflection across the yy-axis
Point Q=(3,4)Q = (-3, -4)
Reflecting across the yy-axis negates the xx-coordinate while keeping the yy-coordinate the same.
2
Perform the vertical translation upward by 22 units
Point R=(3,4+2)=(3,2)R = (-3, -4 + 2) = (-3, -2)
Translating upward adds 22 to the yy-coordinate of point QQ.
3
Determine the quadrant of point RR
Quadrant III
Points with x<0x < 0 and y<0y < 0 are located in Quadrant III.
4
Calculate the distance between point P(3,4)P(3, -4) and point Q(3,4)Q(-3, -4)
Distance = 3(3)=6|3 - (-3)| = 6 units
Points PP and QQ lie on the horizontal line y=4y = -4, so the distance is the difference in their xx-coordinates.

Anahtar Kavram

Coordinate transformations including axis reflections and translations in the Cartesian plane
Soru 1487Soru

In circle OO, points PP and QQ lie on the circumference such that the ratio of the minor arc length PQPQ to the radius rr of the circle is 5π6\frac{5\pi}{6}. If the area of sector POQPOQ is 30π30\pi, what is the total perimeter of sector POQPOQ?

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Cevap: 122+52π12\sqrt{2} + 5\sqrt{2}\pi

Cevap

122+52π12\sqrt{2} + 5\sqrt{2}\pi
The central angle θ\theta in radians is equal to the ratio of minor arc length to radius, so θ=5π6\theta = \frac{5\pi}{6}. Using the area of a sector formula A=12r2θA = \frac{1}{2}r^2\theta, we substitute A=30πA = 30\pi to get 12r2(5π6)=30π\frac{1}{2}r^2\left(\frac{5\pi}{6}\right) = 30\pi, which simplifies to r2=72r^2 = 72, or r=62r = 6\sqrt{2}. The arc length is then s=rθ=(62)(5π6)=52πs = r\theta = (6\sqrt{2})\left(\frac{5\pi}{6}\right) = 5\sqrt{2}\pi. The total perimeter of the sector includes both bounding radii and the arc length: 2r+s=122+52π2r + s = 12\sqrt{2} + 5\sqrt{2}\pi.

Adım Adım Çözüm

1
Relate the central angle in radians to the given ratio of arc length to radius.
The central angle θ\theta in radians is given by θ=arc lengthr=5π6\theta = \frac{\text{arc length}}{r} = \frac{5\pi}{6}.
By definition of radian measure, arc length s=rθs = r\theta, so sr=θ\frac{s}{r} = \theta.
2
Use the sector area formula to solve for the radius rr.
Setting 12r2(5π6)=30π\frac{1}{2}r^2\left(\frac{5\pi}{6}\right) = 30\pi yields 5π12r2=30π    r2=72    r=62\frac{5\pi}{12}r^2 = 30\pi \implies r^2 = 72 \implies r = 6\sqrt{2}.
The area of a sector with central angle θ\theta (in radians) is A=12r2θA = \frac{1}{2}r^2\theta.
3
Calculate the minor arc length ss.
Arc length s=rθ=(62)(5π6)=52πs = r\theta = (6\sqrt{2})\left(\frac{5\pi}{6}\right) = 5\sqrt{2}\pi.
Multiplying the radius by the central angle in radians gives the length of the subtended arc.
4
Calculate the total perimeter of sector POQPOQ.
Perimeter =2r+s=2(62)+52π=122+52π= 2r + s = 2(6\sqrt{2}) + 5\sqrt{2}\pi = 12\sqrt{2} + 5\sqrt{2}\pi.
The perimeter of a sector consists of the two bounding radii plus the arc length.

Anahtar Kavram

Relationship between radian measure, sector area, arc length, and sector perimeter
Tahmini Süre:2m 0s
Soru 1488Soru

A triangle has integer side lengths aa, bb, and cc such that its perimeter is 1818. Which of the following could be the area of the triangle? Select all such values.

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Cevap: 1212; 666\sqrt{6}; 939\sqrt{3}

Cevap

The possible areas of the triangle are 1212, 666\sqrt{6}, and 939\sqrt{3}.
To form a valid triangle with integer sides and a perimeter of 18, each side length must be a positive integer strictly less than 9 by the triangle inequality theorem. Evaluating Heron's formula A=s(sa)(sb)(sc)A = \sqrt{s(s-a)(s-b)(s-c)} with s=9s=9 for all valid side combinations (a,b,c)(a,b,c) produces the set of areas {37,63,315,12,65,66,93}\{3\sqrt{7}, 6\sqrt{3}, 3\sqrt{15}, 12, 6\sqrt{5}, 6\sqrt{6}, 9\sqrt{3}\}. Among the options given, the values 12 (from side lengths 8, 5, 5), 666\sqrt{6} (from side lengths 7, 6, 5), and 939\sqrt{3} (from side lengths 6, 6, 6) are correct.

Adım Adım Çözüm

1
Determine the structural bounds on side lengths using the Triangle Inequality Theorem.
For any side length xx, x<Perimeter2=9x < \frac{\text{Perimeter}}{2} = 9. Thus, a,b,c{1,2,3,4,5,6,7,8}a, b, c \in \{1, 2, 3, 4, 5, 6, 7, 8\}.
The sum of any two side lengths must be strictly greater than the third side length.
2
List all unique integer side length combinations (a,b,c)(a, b, c) where abca \ge b \ge c and a+b+c=18a + b + c = 18.
The valid triples are (8,8,2)(8, 8, 2), (8,7,3)(8, 7, 3), (8,6,4)(8, 6, 4), (8,5,5)(8, 5, 5), (7,7,4)(7, 7, 4), (7,6,5)(7, 6, 5), and (6,6,6)(6, 6, 6).
Exhaustive enumeration of integer partitions of 18 satisfying a8a \le 8.
3
Calculate the semi-perimeter ss of the triangle.
s=182=9s = \frac{18}{2} = 9.
Required parameter for Heron's formula A=s(sa)(sb)(sc)A = \sqrt{s(s-a)(s-b)(s-c)}.
4
Compute the area for candidate triples using Heron's formula.
For (8,5,5)(8, 5, 5): A=9(1)(4)(4)=12A = \sqrt{9(1)(4)(4)} = 12.
For (7,6,5)(7, 6, 5): A=9(2)(3)(4)=66A = \sqrt{9(2)(3)(4)} = 6\sqrt{6}.
For (6,6,6)(6, 6, 6): A=9(3)(3)(3)=93A = \sqrt{9(3)(3)(3)} = 9\sqrt{3}.
Direct evaluation of geometric area for the valid triangles.

Anahtar Kavram

Triangle Inequality Theorem and Area calculation via Heron's Formula
Soru 1489Soru

A dataset of 25 student test scores has a mean of 7070, a standard deviation of 88, and an interquartile range (IQR\text{IQR}) of 1212. A instructor creates a modified dataset by multiplying each original test score by 1.51.5 and then adding 1010 to the result. What is the standard deviation of the modified dataset?

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Cevap: 1212

Cevap

12
For any dataset, if each value xx is transformed into ax+ba \cdot x + b, where aa and bb are constants, the new standard deviation is given by aσold|a| \cdot \sigma_{\text{old}}. In this problem, a=1.5a = 1.5 and b=10b = 10. Therefore, the new standard deviation is 1.5×8=121.5 \times 8 = 12. The addition of 1010 affects measures of center (such as the mean and median) but has no effect on measures of dispersion (such as standard deviation, IQR, and range).

Adım Adım Çözüm

1
Analyze the effect of multiplying each data point by a constant on standard deviation.
Multiplying every value in a dataset by a constant c=1.5c = 1.5 multiplies the standard deviation σ\sigma by c|c|. The new intermediate standard deviation becomes 1.5×8=121.5 \times 8 = 12.
Standard deviation measures dispersion around the mean, so scaling all data points by a factor scales the distance between each point and the mean by that same factor.
2
Analyze the effect of adding a constant to each data point on standard deviation.
Adding a constant k=10k = 10 to every value shifts the entire distribution without changing the distances between data points or the relative spread around the mean. Thus, standard deviation remains 1212.
Adding a constant shifts both the individual values and the mean by the same amount, leaving (xixˉ)(x_i - \bar{x}) unchanged.

Anahtar Kavram

Linear Transformations on Measures of Dispersion
Soru 1490Soru

If xx is an integer that satisfies both 2x915|2x - 9| \le 15 and 52x33\frac{5 - 2x}{-3} \le 3, what is the product of the smallest and largest possible values of xx?

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Cevap: 21-21

Cevap

The product of the smallest and largest possible integer values of xx is 21-21.
Solving 2x915|2x - 9| \le 15 gives 3x12-3 \le x \le 12. Solving 52x33\frac{5 - 2x}{-3} \le 3 requires reversing the inequality sign twice (first when multiplying by 3-3, then when dividing by 2-2), which yields x7x \le 7. Taking the intersection of both intervals gives 3x7-3 \le x \le 7. The smallest integer in this range is 3-3 and the largest is 77, giving a product of (3)×7=21(-3) \times 7 = -21.

Adım Adım Çözüm

1
Solve the absolute value inequality 2x915|2x - 9| \le 15.
152x915    62x24    3x12-15 \le 2x - 9 \le 15 \implies -6 \le 2x \le 24 \implies -3 \le x \le 12.
An absolute value inequality ua|u| \le a (for a0a \ge 0) is equivalent to the compound inequality aua-a \le u \le a.
2
Solve the linear inequality 52x33\frac{5 - 2x}{-3} \le 3.
Multiply by 3-3 and flip the inequality direction: 52x95 - 2x \ge -9. Subtract 55: 2x14-2x \ge -14. Divide by 2-2 and flip the inequality direction again: x7x \le 7.
Multiplying or dividing an inequality by a negative number reverses the direction of the inequality sign.
3
Determine the intersection of the two solution sets.
Combining 3x12-3 \le x \le 12 and x7x \le 7 gives 3x7-3 \le x \le 7.
The value of xx must satisfy both conditions simultaneously.
4
Identify the smallest and largest integer values of xx and calculate their product.
Smallest integer =3= -3, largest integer =7= 7. Product =(3)×7=21= (-3) \times 7 = -21.
Both endpoints 3-3 and 77 are included in the closed interval [3,7][-3, 7].

Anahtar Kavram

Solving compound linear inequalities involving absolute values and applying the rule for reversing inequality signs when multiplying or dividing by negative numbers.
Tahmini Süre:2m 0s
Soru 1491Soru

In the xyxy-plane, line kk passes through the point (1,2)(1, -2) and is perpendicular to line mm, which is defined by the equation 3x4y=123x - 4y = 12. Line kk intersects line nn, defined by the equation y=2x+1y = 2x + 1, at point PP. What is the distance between point PP and the point (3.5,3)(3.5, 3)?

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Cevap: 5

Cevap

5
Rewriting the equation of line mm, 3x4y=123x - 4y = 12, in slope-intercept form gives y=34x3y = \frac{3}{4}x - 3, so line mm has a slope of 34\frac{3}{4}. Since line kk is perpendicular to line mm, its slope is the negative reciprocal, 43-\frac{4}{3}. Using the point (1,2)(1, -2), line kk has the equation y=43x23y = -\frac{4}{3}x - \frac{2}{3}. Setting this equal to the equation of line nn (y=2x+1y = 2x + 1) yields 43x23=2x+1-\frac{4}{3}x - \frac{2}{3} = 2x + 1, which solves to x=0.5x = -0.5 and y=0y = 0, giving the intersection point P(0.5,0)P(-0.5, 0). Finally, calculating the distance between P(0.5,0)P(-0.5, 0) and (3.5,3)(3.5, 3) using the distance formula gives (3.5(0.5))2+(30)2=42+32=25=5\sqrt{(3.5 - (-0.5))^2 + (3 - 0)^2} = \sqrt{4^2 + 3^2} = \sqrt{25} = 5.

Adım Adım Çözüm

1
Determine the slope of line mm
The slope of line mm is 34\frac{3}{4}
Rewriting 3x4y=123x - 4y = 12 in slope-intercept form gives y=34x3y = \frac{3}{4}x - 3, so the slope is 34\frac{3}{4}.
2
Determine the slope of line kk
The slope of line kk is 43-\frac{4}{3}
Perpendicular lines have slopes that are negative reciprocals of each other.
3
Write the equation of line kk
The equation of line kk is y=43x23y = -\frac{4}{3}x - \frac{2}{3}
Using point-slope form with (1,2)(1, -2) gives y(2)=43(x1)y - (-2) = -\frac{4}{3}(x - 1), which simplifies to y=43x23y = -\frac{4}{3}x - \frac{2}{3}.
4
Find the coordinates of intersection point PP
Point PP has coordinates (0.5,0)(-0.5, 0)
Setting 43x23=2x+1-\frac{4}{3}x - \frac{2}{3} = 2x + 1 yields 103x=53    x=0.5-\frac{10}{3}x = \frac{5}{3} \implies x = -0.5. Substituting x=0.5x = -0.5 into y=2x+1y = 2x + 1 yields y=0y = 0.
5
Calculate the distance between P(0.5,0)P(-0.5, 0) and (3.5,3)(3.5, 3)
The distance is 55
Applying the distance formula yields d=(3.5(0.5))2+(30)2=42+32=25=5d = \sqrt{(3.5 - (-0.5))^2 + (3 - 0)^2} = \sqrt{4^2 + 3^2} = \sqrt{25} = 5.

Anahtar Kavram

Perpendicular line slopes, finding intersection of two lines, and applying the distance formula.
Soru 1492Soru

If xx is a real number that satisfies the inequality 3x4+2x+5263|x - 4| + 2|x + 5| \le 26, what is the maximum possible value of x7|x - 7|?

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Cevap: 11

Cevap

11
Solving the piecewise linear inequality 3x4+2x+5263|x - 4| + 2|x + 5| \le 26 yields the interval [4,5.6][-4, 5.6]. The distance function x7|x - 7| reaches its maximum at the endpoint farthest from 77, which is x=4x = -4. Evaluating 47|-4 - 7| yields 11.

Adım Adım Çözüm

1
Identify the critical points of the absolute value terms.
The critical points are x=5x = -5 (where x+5=0x + 5 = 0) and x=4x = 4 (where x4=0x - 4 = 0).
Critical points mark where the linear expressions inside the absolute values change sign.
2
Analyze the inequality piecewise across the three regions defined by the critical points.
For x<5x < -5: 3(4x)+2(5x)26    25x26    x4.83(4 - x) + 2(-5 - x) \le 26 \implies 2 - 5x \le 26 \implies x \ge -4.8. This produces no solution since xx cannot be simultaneously <5< -5 and 4.8\ge -4.8.
For 5x<4-5 \le x < 4: 3(4x)+2(x+5)26    22x26    x43(4 - x) + 2(x + 5) \le 26 \implies 22 - x \le 26 \implies x \ge -4, yielding 4x<4-4 \le x < 4.
For x4x \ge 4: 3(x4)+2(x+5)26    5x226    x5.63(x - 4) + 2(x + 5) \le 26 \implies 5x - 2 \le 26 \implies x \le 5.6, yielding 4x5.64 \le x \le 5.6.
Expanding absolute value terms according to their regional sign definitions removes the absolute values.
3
Combine the valid regional solutions to establish the complete solution interval for xx.
The set of all satisfying real numbers is x[4,5.6]x \in [-4, 5.6].
Taking the union of the non-empty piecewise solution intervals yields the total solution set.
4
Find the maximum value of x7|x - 7| over x[4,5.6]x \in [-4, 5.6].
At x=4x = -4, 47=11=11|-4 - 7| = |-11| = 11. At x=5.6x = 5.6, 5.67=1.4=1.4|5.6 - 7| = |-1.4| = 1.4. The maximum possible value is 11.
The expression x7|x - 7| measures distance from 77. The maximum distance on a closed interval occurs at the endpoint farthest from 77, which is x=4x = -4.

Anahtar Kavram

Piecewise analysis of linear absolute value inequalities and optimization of absolute value distance functions.
Tahmini Süre:2m 30s
Soru 1493Soru

In right triangle PQRPQR, the measure of angle PP is 3030^\circ, the measure of angle QQ is 6060^\circ, and the length of the hypotenuse PRPR is 1212. Which of the following statements must be true? Select all that apply.

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Cevap: The length of the shortest side is 66.; The length of the side opposite the 6060^\circ angle is 636\sqrt{3}.

Cevap

The statements confirming that the shortest side has length 66 and that the side opposite the 6060^\circ angle has length 636\sqrt{3} are both correct.
In any 30609030^\circ-60^\circ-90^\circ right triangle, the sides opposite the 3030^\circ, 6060^\circ, and 9090^\circ angles are in the ratio 1:3:21 : \sqrt{3} : 2. With a hypotenuse of 1212, the side opposite 3030^\circ is 122=6\frac{12}{2} = 6, and the side opposite 6060^\circ is 636\sqrt{3}. Thus, both statements specifying these values are correct.

Adım Adım Çözüm

1
Identify the side length ratio for a 30609030^\circ-60^\circ-90^\circ right triangle.
The side lengths follow the standard ratio 1:3:21 : \sqrt{3} : 2, corresponding to the sides opposite the 3030^\circ, 6060^\circ, and 9090^\circ angles respectively.
Special right triangle properties establish fixed proportional relationships between sides based on interior angles.
2
Calculate the length of the shortest side (opposite the 3030^\circ angle).
Shortest side = Hypotenuse2=122=6\frac{\text{Hypotenuse}}{2} = \frac{12}{2} = 6.
Since the hypotenuse corresponds to 2x=122x = 12, x=6x = 6.
3
Calculate the length of the longer leg (opposite the 6060^\circ angle).
Longer leg = x3=63x\sqrt{3} = 6\sqrt{3}.
The side opposite 6060^\circ is 3\sqrt{3} times the side opposite 3030^\circ.

Anahtar Kavram

Side length ratios of a 30609030^\circ-60^\circ-90^\circ special right triangle (1:3:21 : \sqrt{3} : 2).
Soru 1494Soru

For all real numbers pp and qq, the custom operation \odot is defined by pq=2p23qp \odot q = 2p^2 - 3q. What is the value of 3(4)3 \odot (-4)?

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Cevap: 30

Cevap

The value of 3(4)3 \odot (-4) is 3030.
By applying the definition of the custom operation pq=2p23qp \odot q = 2p^2 - 3q with p=3p = 3 and q=4q = -4, we obtain 2(3)23(4)=2(9)+12=18+12=302(3)^2 - 3(-4) = 2(9) + 12 = 18 + 12 = 30.

Adım Adım Çözüm

1
Substitute p=3p = 3 and q=4q = -4 into the expression 2p23q2p^2 - 3q.
2(3)23(4)2(3)^2 - 3(-4)
The custom operation defines how to process the two inputs pp and qq.
2
Simplify the powers and products according to order of operations.
2(9)(12)=18+122(9) - (-12) = 18 + 12
Exponents must be calculated before multiplication, and multiplying two negative numbers yields a positive value.
3
Add the terms together to get the final numerical result.
3030
18+12=3018 + 12 = 30.

Anahtar Kavram

Custom Symbol Operations
Soru 1495Soru
Consider the linear equation in xx shown below, where kk is a real constant:
xk22x+13=k(x+1)61\frac{x - k}{2} - \frac{2x + 1}{3} = \frac{k(x + 1)}{6} - 1
Which of the following statements must be true? Select all such statements.

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Cevap: If k=1k = 1, then x=0x = 0 is the unique solution to the equation.; If k=0k = 0, the solution to the equation is x=4x = 4.; If k=2k = 2, the solution to the equation is x=43x = -\frac{4}{3}.

Cevap

The correct statements are: if k=1k = 1, then x=0x = 0 is the unique solution; if k=0k = 0, the solution is x=4x = 4; and if k=2k = 2, the solution is x=43x = -\frac{4}{3}.
Multiplying the equation by 66 yields 3(xk)2(2x+1)=k(x+1)63(x - k) - 2(2x + 1) = k(x + 1) - 6. Expanding and collecting terms in xx leads to (k+1)x=4(1k)(k + 1)x = 4(1 - k). Testing the proposed values of kk shows that when k=1k = 1, 2x=02x = 0 gives x=0x = 0; when k=0k = 0, x=4x = 4; and when k=2k = 2, 3x=43x = -4 gives x=43x = -\frac{4}{3}. Therefore, the statements corresponding to k=1k = 1, k=0k = 0, and k=2k = 2 are all correct.

Adım Adım Çözüm

1
Clear fractions by multiplying the entire equation by the least common denominator, 66.
3(xk)2(2x+1)=k(x+1)63(x - k) - 2(2x + 1) = k(x + 1) - 6
Eliminating fractions simplifies algebraic expansion and grouping of like terms.
2
Expand all expressions and combine like terms on both sides.
3x3k4x2=kx+k6    x3k2=kx+k63x - 3k - 4x - 2 = kx + k - 6 \implies -x - 3k - 2 = kx + k - 6
Distribute terms carefully to prevent sign errors.
3
Isolate terms containing xx on one side and parameter/constant terms on the other side.
xkx=k+3k6+2    x(k+1)=4k4    (k+1)x=4(1k)-x - kx = k + 3k - 6 + 2 \implies -x(k + 1) = 4k - 4 \implies (k + 1)x = 4(1 - k)
Factoring out xx provides the general solution form x=4(1k)k+1x = \frac{4(1 - k)}{k + 1} for k1k \neq -1.
4
Evaluate each specified value of kk against (k+1)x=4(1k)(k + 1)x = 4(1 - k).
For k=1k = 1: 2x=0    x=02x = 0 \implies x = 0.
For k=1k = -1: 0x=8    0x = 8 \implies no solution.
For k=0k = 0: 1x=4    x=41x = 4 \implies x = 4.
For k=3k = 3: 4x=8    x=24x = -8 \implies x = -2.
For k=2k = 2: 3x=4    x=433x = -4 \implies x = -\frac{4}{3}.
Direct substitution verifies which given statements are true.

Anahtar Kavram

Solving linear equations with parameters and analyzing existence and uniqueness of solutions.
Tahmini Süre:2m 30s
Soru 1496Soru
Consider the following system of linear equations in xx, yy, and zz, where cc is a real constant:
32xy+2z=5\frac{3}{2}x - y + 2z = 5
x+13yz=2x + \frac{1}{3}y - z = 2
6xy+z=c6x - y + z = c

If the system has at least one solution (x,y,z)(x, y, z), what is the value of 7x23y7x - \frac{2}{3}y?

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Cevap: 18

Cevap

18
To find the value of 7x23y7x - \frac{2}{3}y without individual values for x,y,x, y, and zz, we express 7x23y7x - \frac{2}{3}y as a linear combination m(Eq. 1)+n(Eq. 2)m(\text{Eq. 1}) + n(\text{Eq. 2}). Matching the zz-coefficients requires 2mn=0    n=2m2m - n = 0 \implies n = 2m. Matching the yy-coefficients yields m+13(2m)=23    m=2-m + \frac{1}{3}(2m) = -\frac{2}{3} \implies m = 2, which gives n=4n = 4. Verifying the xx-coefficient gives 2(32)+4(1)=72\left(\frac{3}{2}\right) + 4(1) = 7. Applying these multipliers to the right-hand sides gives 2(5)+4(2)=10+8=182(5) + 4(2) = 10 + 8 = 18.

Adım Adım Çözüm

1
Identify the target expression 7x23y7x - \frac{2}{3}y as a linear combination of the first two equations
Express m(32xy+2z)+n(x+13yz)=7x23y+0zm\left(\frac{3}{2}x - y + 2z\right) + n\left(x + \frac{1}{3}y - z\right) = 7x - \frac{2}{3}y + 0z
Because the system is dependent when consistent, individual variable values cannot be uniquely determined, but specific linear combinations independent of zz can be evaluated.
2
Set up a system of equations for the scalar multipliers mm and nn
Equating coefficients of zz: 2mn=0    n=2m2m - n = 0 \implies n = 2m. Equating coefficients of yy: m+13n=23-m + \frac{1}{3}n = -\frac{2}{3}.
Eliminating zz requires the net coefficient of zz to equal 0.
3
Solve for mm and nn
Substitute n=2mn = 2m into the yy-coefficient equation: m+23m=13m=23    m=2-m + \frac{2}{3}m = -\frac{1}{3}m = -\frac{2}{3} \implies m = 2, which gives n=4n = 4.
Determining the exact linear multipliers needed to match the target expression.
4
Verify xx-coefficient consistency and compute the target value
xx-coefficient: 2(32)+4(1)=3+4=72\left(\frac{3}{2}\right) + 4(1) = 3 + 4 = 7. Value: 2(5)+4(2)=10+8=182(5) + 4(2) = 10 + 8 = 18.
Applying the scalars m=2m = 2 and n=4n = 4 to the right-hand side constants gives the exact numerical value of 7x23y7x - \frac{2}{3}y.

Anahtar Kavram

Linear combinations of dependent systems of equations

Alternatif Yöntem

Multiply the first equation by 2 to clear fractions: 3x2y+4z=103x - 2y + 4z = 10. Multiply the second equation by 3 to clear fractions: 3x+y3z=63x + y - 3z = 6. Eliminate zz by forming 3(3x2y+4z)+4(3x+y3z)=3(10)+4(6)    21x2y=543(3x - 2y + 4z) + 4(3x + y - 3z) = 3(10) + 4(6) \implies 21x - 2y = 54. Dividing both sides of 21x2y=5421x - 2y = 54 by 3 directly gives 7x23y=187x - \frac{2}{3}y = 18.
Tahmini Süre:2m 0s
Soru 1497Soru

In circle OO, sector AOBAOB has an area of 45π45\pi square units and arc ABAB has a length of 6π6\pi units. What is the perimeter of sector AOBAOB?

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Cevap: 30+6π30 + 6\pi

Cevap

30+6π30 + 6\pi
The area of a sector is given by 12rL\frac{1}{2} r L, where rr is the radius and LL is the arc length. Substituting L=6πL = 6\pi and Area =45π= 45\pi yields 45π=12r(6π)45\pi = \frac{1}{2} r (6\pi), which simplifies to 45π=3πr45\pi = 3\pi r, so r=15r = 15. The perimeter of the sector is L+2r=6π+2(15)=30+6πL + 2r = 6\pi + 2(15) = 30 + 6\pi. Thus, the option equal to 30+6π30 + 6\pi is correct.

Adım Adım Çözüm

1
Express sector area and arc length in terms of radius rr and central angle θ\theta in degrees.
Sector Area = θ360×πr2=45π\frac{\theta}{360^\circ} \times \pi r^2 = 45\pi and Arc Length = θ360×2πr=6π\frac{\theta}{360^\circ} \times 2\pi r = 6\pi.
Relating both formulas allows solving for the radius directly using the ratio of area to arc length.
2
Divide the sector area formula by the arc length formula to find radius rr.
\frac{\text{Sector Area}}{\text{Arc Length}} = \frac{\frac{\theta}{360^\circ} \pi r^2}{\frac{\theta}{360^\circ} 2\pi r} = \frac{r}{2} = \frac{45\pi}{6\pi} = 7.5 \implies r = 15.
The central angle fraction θ360\frac{\theta}{360^\circ} and π\pi cancel out, leaving r2=7.5\frac{r}{2} = 7.5.
3
Calculate the total perimeter of sector AOBAOB.
\text{Perimeter} = \text{Arc Length} + 2r = 6\pi + 2(15) = 30 + 6\pi.
The perimeter of a sector consists of the outer arc length plus the two straight boundary radii (OAOA and OBOB).

Anahtar Kavram

The relationship between sector area, arc length, radius, and sector perimeter
Soru 1498Soru

A researcher recorded seven daily temperature readings (in degrees Celsius): 14,5,22,9,25,2,14, 5, 22, 9, 25, 2, and 1717. What is the median of these seven temperature readings?

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Cevap: 1414

Cevap

The median of the temperature readings is 1414.
To find the median of a set of numbers, first arrange them in ascending order: 2,5,9,14,17,22,252, 5, 9, 14, 17, 22, 25. Since there are 77 numbers, the median is the middle value in the 4th4\text{th} position, which is 1414.

Adım Adım Çözüm

1
Arrange the given dataset in ascending numerical order.
The ordered list of 77 temperatures is: 2,5,9,14,17,22,252, 5, 9, 14, 17, 22, 25.
To calculate the median of a dataset, the values must first be ordered from smallest to largest.
2
Identify the middle position for an odd number of data values (n=7n = 7).
The position of the median is 7+12=4th\frac{7 + 1}{2} = 4\text{th} position.
For a dataset with nn elements where nn is odd, the median is located at position n+12\frac{n+1}{2}.
3
Extract the value located at the 4th4\text{th} position in the ordered list.
The 4th4\text{th} term is 1414.
The fourth number in 2,5,9,14,17,22,252, 5, 9, 14, 17, 22, 25 is 1414.

Anahtar Kavram

Median of a Dataset
Tahmini Süre:45s
Soru 1499Soru

In ABC\triangle ABC, the lengths of sides ABAB, BCBC, and ACAC are 1313, 1414, and 1515, respectively. A line segment DEDE is drawn parallel to side BCBC, with point DD lying on side ABAB and point EE lying on side ACAC. If the perimeter of ADE\triangle ADE is equal to the perimeter of quadrilateral DBCEDBCE, what is the area of ADE\triangle ADE?

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Cevap: 47.25

Cevap

47.25
The area of the original triangle ABC\triangle ABC is computed as 8484 using Heron's formula. By defining the linear scale factor kk between ADE\triangle ADE and ABC\triangle ABC, the perimeters of ADE\triangle ADE and quadrilateral DBCEDBCE are expressed as 42k42k and 4214k42 - 14k, respectively. Setting these equal yields k=0.75k = 0.75. The area of ADE\triangle ADE is then k2×84=0.5625×84=47.25k^2 \times 84 = 0.5625 \times 84 = 47.25.

Adım Adım Çözüm

1
Calculate the perimeter and area of the main triangle ABC\triangle ABC.
The perimeter of ABC\triangle ABC is 13+14+15=4213 + 14 + 15 = 42. Using Heron's formula with semi-perimeter s=21s = 21, Area(ABC)=21(2113)(2114)(2115)=21×8×7×6=84\text{Area}(\triangle ABC) = \sqrt{21(21-13)(21-14)(21-15)} = \sqrt{21 \times 8 \times 7 \times 6} = 84.
Finding the area and perimeter of the full triangle sets the required baseline for proportional scaling.
2
Set up expressions for the perimeters of ADE\triangle ADE and quadrilateral DBCEDBCE using a scale factor kk.
Because DEBCDE \parallel BC, ADEABC\triangle ADE \sim \triangle ABC with scale factor k=ADAB=AEAC=DEBCk = \frac{AD}{AB} = \frac{AE}{AC} = \frac{DE}{BC}. Thus, Perimeter(ADE)=13k+15k+14k=42k\text{Perimeter}(\triangle ADE) = 13k + 15k + 14k = 42k. The segments DB=13(1k)DB = 13(1-k) and EC=15(1k)EC = 15(1-k), so Perimeter(DBCE)=13(1k)+14+15(1k)+14k=4214k\text{Perimeter}(DBCE) = 13(1-k) + 14 + 15(1-k) + 14k = 42 - 14k.
Parallel lines create similar triangles, which allows all perimeter segment lengths to be represented in terms of one variable kk.
3
Solve for the scale factor kk by equating the two perimeters.
42k=4214k    56k=42    k=4256=34=0.7542k = 42 - 14k \implies 56k = 42 \implies k = \frac{42}{56} = \frac{3}{4} = 0.75.
Equating the perimeters satisfies the condition specified in the question stem.
4
Calculate the area of ADE\triangle ADE using the square of the linear scale factor.
Area(ADE)=k2×Area(ABC)=(34)2×84=916×84=1894=47.25\text{Area}(\triangle ADE) = k^2 \times \text{Area}(\triangle ABC) = \left(\frac{3}{4}\right)^2 \times 84 = \frac{9}{16} \times 84 = \frac{189}{4} = 47.25.
The area ratio of similar geometric figures is proportional to the square of their linear scale factor.

Anahtar Kavram

Properties of Similar Triangles, Area via Heron's Formula, and Perimeter Scaling
Soru 1500Soru

A manufacturing facility uses Machine A and Machine B to process standard orders of raw materials. Operating independently at its constant rate, Machine A requires xx hours to process one standard order, where x>0x > 0. Machine B operates at a constant rate and requires x+2x + 2 hours to process one standard order. When both machines operate simultaneously at their respective constant rates for 66 hours, the total number of standard orders processed is 22 fewer than the number of standard orders Machine A would process operating alone for 1818 hours. What is the value of xx?

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Cevap: 4

Cevap

4
The rate of Machine A is 1x\frac{1}{x} orders per hour, and the rate of Machine B is 1x+2\frac{1}{x+2} orders per hour. In 18 hours, Machine A processes 18x\frac{18}{x} orders. Working together for 6 hours, both machines process 6(1x+1x+2)6\left(\frac{1}{x} + \frac{1}{x+2}\right) orders. Setting up the difference: 18x6(1x+1x+2)=2\frac{18}{x} - 6\left(\frac{1}{x} + \frac{1}{x+2}\right) = 2, which simplifies to 12x6x+2=2\frac{12}{x} - \frac{6}{x+2} = 2. Multiplying both sides by x(x+2)x(x+2) yields 12(x+2)6x=2x2+4x12(x+2) - 6x = 2x^2 + 4x, leading to 2x22x24=02x^2 - 2x - 24 = 0 or x2x12=0x^2 - x - 12 = 0. Factoring gives (x4)(x+3)=0(x-4)(x+3) = 0. Because time must be positive, x=4x = 4.

Adım Adım Çözüm

1
Express the individual work rates of Machine A and Machine B.
Machine A completes 1x\frac{1}{x} orders per hour; Machine B completes 1x+2\frac{1}{x+2} orders per hour.
Work rate is the reciprocal of the total time required to complete one unit of work.
2
Formulate the equation based on the total orders processed in the given time frames.
181x6(1x+1x+2)=218 \cdot \frac{1}{x} - 6\left(\frac{1}{x} + \frac{1}{x+2}\right) = 2
Machine A alone in 18 hours processes 18x\frac{18}{x} orders. Together in 6 hours, they process 6(1x+1x+2)6\left(\frac{1}{x} + \frac{1}{x+2}\right) orders, which is 2 orders less.
3
Simplify the algebraic equation.
12x6x+2=2\frac{12}{x} - \frac{6}{x+2} = 2
Subtracting 61x6 \cdot \frac{1}{x} from 181x18 \cdot \frac{1}{x} yields 12x\frac{12}{x}.
4
Clear the denominators by multiplying through by x(x+2)x(x+2) and solve the resulting quadratic equation.
12(x+2)6x=2x(x+2)    6x+24=2x2+4x    2x22x24=0    x2x12=0    (x4)(x+3)=012(x+2) - 6x = 2x(x+2) \implies 6x + 24 = 2x^2 + 4x \implies 2x^2 - 2x - 24 = 0 \implies x^2 - x - 12 = 0 \implies (x-4)(x+3) = 0
Clearing denominators transforms the rational equation into a standard quadratic equation.
5
Select the physically meaningful solution for time xx.
x=4x = 4 hours (rejecting x=3x = -3 since x>0x > 0).
Time must be positive.

Anahtar Kavram

Algebraic Work-Rate Modeling and Quadratic Solution
Tahmini Süre:2m 0s
ÖncekiSayfa 75 / 107Sonraki
Tüm alıştırma soruları — GRE General Test | Examkin