Algebra

356 soru

Soru 221Soru

A parabola defined by the quadratic function f(x)=ax2+bx+cf(x) = ax^2 + bx + c, where a,b,a, b, and cc are real constants with a>0a > 0, has its vertex at a minimum value of 16-16. The distance between the two xx-intercepts of the parabola is 88. If f(1)=7f(1) = -7 and the xx-coordinate of the vertex is positive, what is the value of f(2)f(-2)?

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Cevap: 20

Cevap

The value of f(2)f(-2) is 20.
By converting the parabola into vertex form f(x)=a(xh)216f(x) = a(x - h)^2 - 16, the xx-intercepts are found at h±4ah \pm \frac{4}{\sqrt{a}}. Equating their difference to 88 yields a=1a = 1. Substituting f(1)=7f(1) = -7 gives (1h)2=9(1 - h)^2 = 9, which yields h=4h = 4 under the condition h>0h > 0. Evaluating f(2)=(24)216f(-2) = (-2 - 4)^2 - 16 produces 2020.

Adım Adım Çözüm

1
Express the quadratic function in vertex form using the minimum value
f(x)=a(xh)216f(x) = a(x - h)^2 - 16, where (h,16)(h, -16) is the vertex.
Since a>0a > 0, the parabola opens upwards and its minimum value occurs at the vertex yy-coordinate, k=16k = -16.
2
Determine the leading coefficient aa using the distance between xx-intercepts
a=1a = 1
Setting f(x)=0f(x) = 0 yields a(xh)216=0    (xh)2=16a    x=h±4aa(x - h)^2 - 16 = 0 \implies (x - h)^2 = \frac{16}{a} \implies x = h \pm \frac{4}{\sqrt{a}}. The distance between roots is 8a=8\frac{8}{\sqrt{a}} = 8, which gives a=1    a=1\sqrt{a} = 1 \implies a = 1.
3
Determine the vertex xx-coordinate hh using the point f(1)=7f(1) = -7
h=4h = 4
Substituting a=1a = 1 and x=1x = 1 into the vertex form gives (1h)216=7    (1h)2=9(1 - h)^2 - 16 = -7 \implies (1 - h)^2 = 9. Taking square roots gives 1h=3    h=21 - h = 3 \implies h = -2 or 1h=3    h=41 - h = -3 \implies h = 4. Since h>0h > 0, we select h=4h = 4.
4
Evaluate f(2)f(-2) using the fully specified function
f(2)=20f(-2) = 20
With f(x)=(x4)216f(x) = (x - 4)^2 - 16, substituting x=2x = -2 yields f(2)=(24)216=(6)216=3616=20f(-2) = (-2 - 4)^2 - 16 = (-6)^2 - 16 = 36 - 16 = 20.

Anahtar Kavram

Quadratic Vertex Form, Root Separation, and Evaluation
Soru 222Soru

For all real numbers xx and yy, the custom binary operation \odot is defined by xy=x+yxyx \odot y = x + y - xy. Which of the following statements must be true for all real numbers aa, bb, and cc? Select all such statements.

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Cevap: ab=baa \odot b = b \odot a; a1=1a \odot 1 = 1; (ab)c=a(bc)(a \odot b) \odot c = a \odot (b \odot c)

Cevap

The statements ab=baa \odot b = b \odot a, a1=1a \odot 1 = 1, and (ab)c=a(bc)(a \odot b) \odot c = a \odot (b \odot c) must be true for all real numbers aa, bb, and cc.
The custom operation is commutative (ab=baa \odot b = b \odot a), maps any real number operated with 11 to 11 (a1=1a \odot 1 = 1), and is associative ((ab)c=a(bc)(a \odot b) \odot c = a \odot (b \odot c)). These three properties hold universally for all real numbers.

Adım Adım Çözüm

1
Evaluate aba \odot b and bab \odot a to test commutativity.
ab=a+baba \odot b = a + b - ab and ba=b+abab \odot a = b + a - ba. Since addition and multiplication of real numbers are commutative, a+bab=b+abaa + b - ab = b + a - ba.
Verify if order of operands alters the result.
2
Evaluate a1a \odot 1 using the operation definition.
a1=a+1a(1)=a+1a=1a \odot 1 = a + 1 - a(1) = a + 1 - a = 1.
Test the behavior of operating with the constant 11.
3
Evaluate a0a \odot 0 to verify the zero property statement.
a0=a+0a(0)=aa \odot 0 = a + 0 - a(0) = a. This equals aa, not 00 for general values of aa.
Check if operating with 00 results in 00.
4
Evaluate both sides of (ab)c=a(bc)(a \odot b) \odot c = a \odot (b \odot c) to test associativity.
Left side: (ab)c=(a+bab)c=(a+bab)+c(a+bab)c=a+b+cabacbc+abc(a \odot b) \odot c = (a + b - ab) \odot c = (a + b - ab) + c - (a + b - ab)c = a + b + c - ab - ac - bc + abc. Right side: a(bc)=a(b+cbc)=a+(b+cbc)a(b+cbc)=a+b+cbcabac+abca \odot (b \odot c) = a \odot (b + c - bc) = a + (b + c - bc) - a(b + c - bc) = a + b + c - bc - ab - ac + abc. Both sides are identical.
Verify whether grouping alters the result.
5
Evaluate aaa \odot a.
aa=a+aa(a)=2aa2a \odot a = a + a - a(a) = 2a - a^2. This is not equal to a2a^2 except when 2aa2=a2    2a22a=0    a=02a - a^2 = a^2 \implies 2a^2 - 2a = 0 \implies a=0 or a=1a=1.
Determine if the self-operation yields a2a^2 for all real numbers.

Anahtar Kavram

Evaluating algebraic properties (commutativity, identity, associativity) of custom binary operations.
Soru 223Soru

A rectangular plot of land has a perimeter of 56 meters and an area of 180 square meters. A border of uniform width xx meters is constructed around the inside edge of the plot, reducing the remaining inner area to 84 square meters. What is the value of xx?

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Cevap: 2

Cevap

The border width x is 2 meters.
Solving the system L+W=28L + W = 28 and LW=180LW = 180 gives outer dimensions of 18 and 10 meters. The inner area equation (182x)(102x)=84(18 - 2x)(10 - 2x) = 84 simplifies to x214x+24=0x^2 - 14x + 24 = 0, which factors into (x2)(x12)=0(x - 2)(x - 12) = 0. Since 2x2x must be less than the total width of 10 meters (x<5x < 5), the extraneous root x=12x = 12 is discarded, leaving x=2x = 2.

Adım Adım Çözüm

1
Determine the outer dimensions of the plot.
Length = 18 meters, Width = 10 meters
The semi-perimeter is L + W = 56 / 2 = 28, and the area is L * W = 180. Forming the quadratic equation t^2 - 28t + 180 = 0 yields roots t = 18 and t = 10.
2
Write the quadratic expression for the inner area in terms of x.
(18 - 2x)(10 - 2x) = 84
A uniform border of width x along all four sides reduces both the length and width by 2x.
3
Expand and simplify the quadratic equation into standard form.
x^2 - 14x + 24 = 0
Expanding yields 180 - 56x + 4x^2 = 84. Subtracting 84 gives 4x^2 - 56x + 96 = 0, which divides by 4 to give x^2 - 14x + 24 = 0.
4
Factor the quadratic equation to solve for possible values of x.
x = 2 or x = 12
Factoring x^2 - 14x + 24 = 0 gives (x - 2)(x - 12) = 0.
5
Eliminate the extraneous root based on physical geometry constraints.
x = 2
The total width is 10 meters, so 2x must be less than 10 (x < 5). Thus, x = 12 is physically impossible and discarded.

Anahtar Kavram

Quadratic Equations, Factoring, and Extraneous Solutions
Soru 224Soru

In the xyxy-plane, line LL passes through the points (t,t+2)(t, t+2) and (3t1,2t+7)(3t-1, 2t+7), where tt is a constant. Line MM is perpendicular to line LL and passes through the point (4,1)(4, -1). If the yy-intercept of line MM is 1111, what is the value of tt?

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Cevap: 16-16

Cevap

16-16
The slope of line M is computed from its yy-intercept (0,11)(0, 11) and the point (4,1)(4, -1) as 11(1)04=3\frac{11 - (-1)}{0 - 4} = -3. Because line L is perpendicular to line M, the slope of line L is the negative reciprocal of 3-3, which is 13\frac{1}{3}. Calculating the slope of line L using points (t,t+2)(t, t+2) and (3t1,2t+7)(3t-1, 2t+7) gives (2t+7)(t+2)(3t1)t=t+52t1\frac{(2t+7)-(t+2)}{(3t-1)-t} = \frac{t+5}{2t-1}. Setting t+52t1=13\frac{t+5}{2t-1} = \frac{1}{3} leads to 3t+15=2t13t + 15 = 2t - 1, which simplifies to t=16t = -16.

Adım Adım Çözüm

1
Determine the slope of line M using its given points.
Line M passes through (4,1)(4, -1) and its yy-intercept (0,11)(0, 11). The slope mM=11(1)04=124=3m_M = \frac{11 - (-1)}{0 - 4} = \frac{12}{-4} = -3.
The slope of a line through (x1,y1)(x_1, y_1) and (x2,y2)(x_2, y_2) is given by y2y1x2x1\frac{y_2 - y_1}{x_2 - x_1}.
2
Determine the required slope of line L.
Since line L is perpendicular to line M, its slope mL=1mM=13=13m_L = -\frac{1}{m_M} = -\frac{1}{-3} = \frac{1}{3}.
Perpendicular lines in the coordinate plane have slopes that are negative reciprocals of each other.
3
Express the slope of line L in terms of tt and solve for tt.
Using points (t,t+2)(t, t+2) and (3t1,2t+7)(3t-1, 2t+7), mL=(2t+7)(t+2)(3t1)t=t+52t1m_L = \frac{(2t+7) - (t+2)}{(3t-1) - t} = \frac{t+5}{2t-1}. Setting t+52t1=13\frac{t+5}{2t-1} = \frac{1}{3} yields 3(t+5)=1(2t1)    3t+15=2t1    t=163(t+5) = 1(2t-1) \implies 3t + 15 = 2t - 1 \implies t = -16.
Equating the algebraic slope expression to the numerical slope allows solving for the unknown parameter tt.

Anahtar Kavram

Perpendicular Slopes and Coordinate Line Equations
Tahmini Süre:2m 0s
Soru 225Soru

Which of the following values of xx satisfy the inequality 63x>9|6 - 3x| > 9? Select all that apply.

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Cevap: 4-4; 2-2; 66

Cevap

The values 4-4, 2-2, and 66 satisfy the inequality 63x>9|6 - 3x| > 9.
The absolute value inequality 63x>9|6 - 3x| > 9 is equivalent to 63x>96 - 3x > 9 or 63x<96 - 3x < -9. Solving these yields x<1x < -1 or x>5x > 5. Among the given choices, 4-4, 2-2, and 66 fall within these solution ranges.

Adım Adım Çözüm

1
Set up the compound linear inequalities from the absolute value inequality 63x>9|6 - 3x| > 9.
63x>96 - 3x > 9 or 63x<96 - 3x < -9
An absolute value inequality of the form u>c|u| > c (where c>0c > 0) splits into u>cu > c or u<cu < -c.
2
Solve the first inequality 63x>96 - 3x > 9.
3x>3    x<1-3x > 3 \implies x < -1
Subtracting 66 gives 3x>3-3x > 3. Dividing both sides by 3-3 reverses the inequality sign to yield x<1x < -1.
3
Solve the second inequality 63x<96 - 3x < -9.
3x<15    x>5-3x < -15 \implies x > 5
Subtracting 66 gives 3x<15-3x < -15. Dividing both sides by 3-3 reverses the inequality sign to yield x>5x > 5.
4
Combine the solution sets and evaluate the given options.
The solution set consists of all real numbers where x<1x < -1 or x>5x > 5. Therefore, 4-4, 2-2, and 66 are valid solutions.
Values 4-4 and 2-2 are strictly less than 1-1, while 66 is strictly greater than 55.

Anahtar Kavram

Solving absolute value inequalities and reversing inequality signs when multiplying or dividing by negative numbers.
Soru 226Soru

A logistics company uses two delivery vehicles, Vehicle P and Vehicle Q, to transport cargo between two warehouses that are 240240 miles apart. Vehicle P travels at a constant average speed of rr miles per hour (r>0r > 0). Vehicle Q travels at a constant average speed that is 2020 miles per hour faster than that of Vehicle P. In addition to driving time, Vehicle P requires a flat setup time of 11 hour before departure, while Vehicle Q requires a flat setup time of 22 hours before departure.

Let TP(r)T_P(r) and TQ(r)T_Q(r) represent the total elapsed time in hours (including setup time) required for Vehicle P and Vehicle Q to complete the trip, respectively.

Which of the following statements are true? Select all such statements.

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Cevap: The total elapsed time for Vehicle P, in hours, as a function of its speed rr, is given by TP(r)=240+rrT_P(r) = \frac{240 + r}{r}.; Vehicle P and Vehicle Q take the exact same total elapsed time to complete the trip when r=60r = 60 miles per hour.

Cevap

The correct statements are the algebraic expression for Vehicle P's total time as a function of speed and the equal total elapsed time condition at a speed of 60 miles per hour.
The expression for Vehicle P's total time accurately combines 11 hour of setup time with 240r\frac{240}{r} driving hours to get 240+rr\frac{240+r}{r}. Setting TP(r)=TQ(r)T_P(r) = T_Q(r) yields the quadratic equation r2+20r4800=0r^2 + 20r - 4800 = 0, which correctly solves to r=60r = 60 mph, at which point both vehicles require exactly 55 hours total.

Adım Adım Çözüm

1
Model total elapsed time functions TP(r)T_P(r) and TQ(r)T_Q(r) using setup time plus travel time.
TP(r)=1+240r=240+rrT_P(r) = 1 + \frac{240}{r} = \frac{240 + r}{r} and TQ(r)=2+240r+20T_Q(r) = 2 + \frac{240}{r + 20}.
Total elapsed time is the sum of fixed pre-departure setup overhead and variable driving time.
2
Determine the speed rr where total elapsed times are equal by setting TP(r)=TQ(r)T_P(r) = T_Q(r).
1+240r=2+240r+20    240r240r+20=1    24020=r(r+20)    r2+20r4800=01 + \frac{240}{r} = 2 + \frac{240}{r + 20} \implies \frac{240}{r} - \frac{240}{r + 20} = 1 \implies 240 \cdot 20 = r(r + 20) \implies r^2 + 20r - 4800 = 0. Factoring gives (r60)(r+80)=0(r - 60)(r + 80) = 0, so r=60r = 60 mph.
Solving the rational equation identifies the exact breakeven speed where higher travel efficiency balances extra setup time.
3
Evaluate the remaining candidate assertions against the derived model.
For r>60r > 60, TQ(r)>TP(r)T_Q(r) > T_P(r), invalidating the claim that Vehicle Q is always faster. At r=40r = 40, TP(40)=7T_P(40) = 7 hours and TP(80)=4T_P(80) = 4 hours, giving a decrease of 3742.86%\frac{3}{7} \approx 42.86\%, invalidating the 50%50\% reduction claim.
Fixed setup costs distort simple constant-proportion and percentage changes in total time.

Anahtar Kavram

Algebraic Modeling of Combined Time with Fixed Overhead and Variable Rates
Soru 227Soru

If xx is an integer that satisfies both 2x19|2x - 1| \le 9 and x+23>2\frac{x + 2}{-3} > -2, how many possible values of xx exist?

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Cevap: 8

Cevap

There are 8 possible integer values for x.
Solving 2x19|2x - 1| \le 9 yields 4x5-4 \le x \le 5. Solving x+23>2\frac{x + 2}{-3} > -2 requires flipping the inequality sign when multiplying by 3-3, which gives x<4x < 4. Combining both inequalities yields 4x<4-4 \le x < 4. The integers satisfying this compound inequality are 4,3,2,1,0,1,2,3-4, -3, -2, -1, 0, 1, 2, 3, making a total of 8 possible integer values.

Adım Adım Çözüm

1
Solve the absolute value inequality 2x19|2x - 1| \le 9
92x19    82x10    4x5-9 \le 2x - 1 \le 9 \implies -8 \le 2x \le 10 \implies -4 \le x \le 5
An absolute value inequality of the form uk|u| \le k expands to kuk-k \le u \le k.
2
Solve the linear inequality x+23>2\frac{x + 2}{-3} > -2
x+2<6    x<4x + 2 < 6 \implies x < 4
Multiplying both sides of an inequality by a negative quantity (3-3) requires reversing the inequality sign from >> to <<.
3
Find the intersection of the two solution sets
4x<4-4 \le x < 4
The integer xx must satisfy both 4x5-4 \le x \le 5 and x<4x < 4 simultaneously.
4
Count the integer values satisfying 4x<4-4 \le x < 4
The integers are 4,3,2,1,0,1,2,3-4, -3, -2, -1, 0, 1, 2, 3, which totals 8 values.
Counting all integers from 4-4 up to (but not including) 44 gives 8 valid integers.

Anahtar Kavram

Solving systems of linear inequalities involving absolute values and negative multipliers
Tahmini Süre:1m 30s
Soru 228Soru

A water purification facility uses a primary filtration system and a secondary filtration system to process untreated water. The primary system operates at a constant rate that is 25%25\% faster than the secondary system. Working together at their normal constant rates, both systems can process a full reservoir of 36,00036,000 gallons in 88 hours.

On a day when the primary system operates at only 80%80\% of its normal rate due to maintenance while the secondary system operates at its normal rate, both systems work together for 66 hours. At that point, the primary system is shut down completely. How many additional hours will it take the secondary system, working alone at its normal rate, to process the remainder of the reservoir?

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Cevap: 6.06.0 hours

Cevap

6.06.0 hours
The correct answer of 6.06.0 hours is derived by establishing that the combined normal processing rate is 4,5004,500 gal/hr. Since the primary system is 25%25\% faster than the secondary system (P=1.25SP = 1.25S), the secondary rate is 2,0002,000 gal/hr and the primary rate is 2,5002,500 gal/hr. At 80%80\% efficiency, the primary system operates at 2,0002,000 gal/hr, making the joint rate 4,0004,000 gal/hr. In 66 hours, 24,00024,000 gallons are processed, leaving 12,00012,000 gallons. The secondary system working alone at 2,0002,000 gal/hr processes the remaining volume in exactly 6.06.0 hours.

Adım Adım Çözüm

1
Determine the combined normal operating rate and set up individual rates.
Combined rate = 4,5004,500 gal/hr; Secondary rate = 2,0002,000 gal/hr; Primary rate = 2,5002,500 gal/hr.
The combined rate is 36,000 gallons8 hours=4,500 gal/hr\frac{36,000\text{ gallons}}{8\text{ hours}} = 4,500\text{ gal/hr}. Let SS be the secondary rate. The primary rate is 1.25S1.25S. Thus, S+1.25S=2.25S=4,500S + 1.25S = 2.25S = 4,500, yielding S=2,000 gal/hrS = 2,000\text{ gal/hr} and P=2,500 gal/hrP = 2,500\text{ gal/hr}.
2
Calculate the reduced primary rate and the total water processed in the first 6 hours.
24,00024,000 gallons processed in the first 6 hours.
During maintenance, the primary system operates at 80%80\% of 2,500 gal/hr2,500\text{ gal/hr}, which is 0.80×2,500=2,000 gal/hr0.80 \times 2,500 = 2,000\text{ gal/hr}. The combined rate during this period is 2,000+2,000=4,000 gal/hr2,000 + 2,000 = 4,000\text{ gal/hr}. Over 6 hours, the volume processed is 4,000×6=24,000 gallons4,000 \times 6 = 24,000\text{ gallons}.
3
Find the remaining volume of water to process.
12,00012,000 gallons remaining.
Subtract the volume processed from the total reservoir capacity: 36,00024,000=12,000 gallons36,000 - 24,000 = 12,000\text{ gallons}.
4
Calculate the time required for the secondary system alone to process the remainder.
6.06.0 hours.
Divide the remaining volume by the normal secondary system rate S=2,000 gal/hrS = 2,000\text{ gal/hr}: 12,000 gallons2,000 gal/hr=6.0 hours\frac{12,000\text{ gallons}}{2,000\text{ gal/hr}} = 6.0\text{ hours}.

Anahtar Kavram

Linear rate modeling and percentage rate adjustment in combined work problems
Tahmini Süre:2m 30s
Soru 229Soru

Consider the quadratic equation x22(k+1)x+(k2+4k+1)=0x^2 - 2(k + 1)x + (k^2 + 4k + 1) = 0, where kk is a real constant. Let α\alpha and β\beta be the real roots of this equation. If α2+β2=18\alpha^2 + \beta^2 = 18, what is the sum of all possible values of kk?

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Cevap: 22-2\sqrt{2}

Cevap

The sum of all possible real values of kk is 22-2\sqrt{2}.
Using Vieta's formulas, α+β=2(k+1)\alpha + \beta = 2(k + 1) and αβ=k2+4k+1\alpha\beta = k^2 + 4k + 1. Expanding α2+β2=(α+β)22αβ\alpha^2 + \beta^2 = (\alpha + \beta)^2 - 2\alpha\beta gives 2k2+22k^2 + 2. Setting 2k2+2=182k^2 + 2 = 18 yields k2=8k^2 = 8, so k=±22k = \pm 2\sqrt{2}. Furthermore, for the roots α\alpha and β\beta to be real numbers, the discriminant Δ=[2(k+1)]24(k2+4k+1)=8k\Delta = [-2(k+1)]^2 - 4(k^2+4k+1) = -8k must be non-negative, requiring k0k \le 0. Only k=22k = -2\sqrt{2} satisfies this requirement. Hence, the sum of all valid values of kk is 22-2\sqrt{2}.

Adım Adım Çözüm

1
Apply Vieta's formulas to express the sum and product of roots in terms of kk.
α+β=2(k+1)\alpha + \beta = 2(k + 1) and αβ=k2+4k+1\alpha\beta = k^2 + 4k + 1.
For any quadratic equation x2bx+c=0x^2 - bx + c = 0, the sum of roots is bb and the product of roots is cc.
2
Express α2+β2\alpha^2 + \beta^2 in terms of kk using the algebraic identity (α+β)22αβ(\alpha + \beta)^2 - 2\alpha\beta.
α2+β2=[2(k+1)]22(k2+4k+1)=4(k2+2k+1)2k28k2=2k2+2\alpha^2 + \beta^2 = [2(k + 1)]^2 - 2(k^2 + 4k + 1) = 4(k^2 + 2k + 1) - 2k^2 - 8k - 2 = 2k^2 + 2.
Expanding and simplifying allows us to relate the given sum of squares to the parameter kk.
3
Set the simplified expression equal to 1818 and solve for kk.
2k2+2=18    2k2=16    k2=8    k=±222k^2 + 2 = 18 \implies 2k^2 = 16 \implies k^2 = 8 \implies k = \pm 2\sqrt{2}.
This yields two candidate real values for the parameter kk.
4
Analyze the discriminant Δ\Delta to enforce the condition that roots α\alpha and β\beta are real numbers.
Δ=[2(k+1)]24(1)(k2+4k+1)=4(k2+2k+1)4(k2+4k+1)=8k\Delta = [-2(k + 1)]^2 - 4(1)(k^2 + 4k + 1) = 4(k^2 + 2k + 1) - 4(k^2 + 4k + 1) = -8k. For real roots, Δ0    8k0    k0\Delta \ge 0 \implies -8k \ge 0 \implies k \le 0.
A quadratic equation has real roots if and only if its discriminant is non-negative.
5
Filter candidate values of kk against the condition k0k \le 0.
k=22k = -2\sqrt{2} satisfies k0k \le 0 (yielding Δ=162>0\Delta = 16\sqrt{2} > 0), while k=22k = 2\sqrt{2} fails k0k \le 0 (yielding Δ=162<0\Delta = -16\sqrt{2} < 0). Thus, k=22k = -2\sqrt{2} is the unique valid value.
Values of kk that make the discriminant negative produce non-real complex roots and must be discarded as extraneous.

Anahtar Kavram

Quadratic Vieta's formulas combined with discriminant non-negativity constraint for real roots
Tahmini Süre:2m 30s
Soru 230Soru

A theater sold a total of 500500 tickets for an evening performance, consisting of VIP tickets priced at $80\$80 each and General Admission tickets priced at $50\$50 each. On the day of the show, a promotional discount of 20%20\% was applied to all General Admission tickets, while VIP ticket prices remained unchanged. If the total revenue collected from ticket sales was $31,000\$31,000, which of the following statements must be true? Select all such statements.

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Cevap: More than 70% of the total revenue was generated from VIP ticket sales.; The number of VIP tickets sold was 50 greater than the number of General Admission tickets sold.

Cevap

The statements confirming that more than 70% of total revenue came from VIP ticket sales and that 50 more VIP tickets were sold than General Admission tickets are correct.
The system of equations V+G=500V + G = 500 and 80V+40G=31,00080V + 40G = 31,000 yields V=275V = 275 VIP tickets and G=225G = 225 General Admission tickets. The VIP revenue is 22,000,whichisapproximately70.9722,000, which is approximately 70.97% of the total 31,000 revenue (greater than 70%). Additionally, the difference 275225=50275 - 225 = 50 confirms that 50 more VIP tickets were sold than General Admission tickets.

Adım Adım Çözüm

1
Define variables and determine the discounted price of General Admission tickets.
Let VV be the number of VIP tickets and GG be the number of General Admission tickets. The discounted price for General Admission tickets is $50×(10.20)=$40\$50 \times (1 - 0.20) = \$40.
Establishing correct variable representations and effective unit prices is required to build the revenue model.
2
Set up and solve the system of linear equations.
V+G=500V + G = 500 and 80V+40G=31,00080V + 40G = 31,000. Substituting G=500VG = 500 - V gives 80V+40(500V)=31,000    40V=11,000    V=27580V + 40(500 - V) = 31,000 \implies 40V = 11,000 \implies V = 275. Thus, G=225G = 225.
Solving the linear system determines the exact quantity of each ticket type sold.
3
Calculate revenue shares and verify each statement.
VIP revenue = 275×$80=$22,000275 \times \$80 = \$22,000. Revenue share of VIP = 22,00031,00070.97%>70%\frac{22,000}{31,000} \approx 70.97\% > 70\%. Ticket difference = 275225=50275 - 225 = 50. Ratio V:G=275:225=11:9V:G = 275:225 = 11:9.
Evaluating each calculated metric against the given statements determines which statements must be true.

Anahtar Kavram

Linear word problems involving systems of equations and percentage modifications.
Tahmini Süre:2m 0s
Soru 231Soru

A manufacturing plant operates two automated production lines, Assembly Line X and Assembly Line Y. Assembly Line Y operates at a standard rate that is 25%25\% faster than the standard rate of Assembly Line X. During a specific shift, Assembly Line X operated for 44 hours at its standard rate, after which its processing rate decreased by 20%20\% for an additional 22 hours due to maintenance. Assembly Line Y began operating 11 hour after Line X started; it operated at its standard rate for 44 hours, and then operated for another 22 hours at 80%80\% of its standard rate. If the two lines produced a combined total of 2,7722,772 units during this shift, what was the standard operating rate of Assembly Line X, in units per hour?

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Cevap: 220

Cevap

The standard operating rate of Assembly Line X is 220 units per hour.
Assembly Line X produces 4r4r units in its first 4 hours and 1.6r1.6r units in its final 2 hours, totaling 5.6r5.6r units. Assembly Line Y produces 4×1.25r=5r4 \times 1.25r = 5r units in its first 4 hours and 2×(0.80×1.25r)=2r2 \times (0.80 \times 1.25r) = 2r units in its final 2 hours, totaling 7r7r units. The sum of their outputs is 5.6r+7r=12.6r=2,7725.6r + 7r = 12.6r = 2,772. Dividing 2,7722,772 by 12.612.6 gives r=220r = 220.

Adım Adım Çözüm

1
Set up rate expressions for both assembly lines using a single variable
Standard rate of Line X = rr; Standard rate of Line Y = 1.25r1.25r
Line Y is 25% faster than Line X, so its rate is r+0.25r=1.25rr + 0.25r = 1.25r.
2
Calculate the total work done by Assembly Line X
Line X output = 4(r)+2(0.80r)=5.6r4(r) + 2(0.80r) = 5.6r units
Line X worked 4 hours at 100% rate and 2 hours at 80% rate.
3
Calculate the total work done by Assembly Line Y
Line Y output = 4(1.25r)+2(0.80×1.25r)=5r+2r=7r4(1.25r) + 2(0.80 \times 1.25r) = 5r + 2r = 7r units
Line Y worked 4 hours at full rate 1.25r1.25r and 2 hours at 80% of 1.25r1.25r, which equals rate rr.
4
Equate combined production to 2,772 units and solve for rr
5.6r+7r=12.6r=2,772    r=2205.6r + 7r = 12.6r = 2,772 \implies r = 220
Dividing the total combined output by the total rate multiplier 12.6 yields the baseline standard rate.

Anahtar Kavram

Algebraic Modeling of Staggered Work and Variable Production Rates
Tahmini Süre:2m 30s
Soru 232Soru

For all positive real numbers xx and yy, the custom operation \star is defined by xy=x2+y2xyx \star y = \frac{x^2 + y^2}{xy}. The function gg is defined by g(t)=4(t3)7g(t) = 4(t \star 3) - 7. If g(k)=3g(k) = 3, where k>3k > 3, what is the value of kk?

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Cevap: 6

Cevap

The value of kk is 6.
Solving g(k)=3g(k) = 3 yields 4(k3)7=34(k \star 3) - 7 = 3, so k3=52k \star 3 = \frac{5}{2}. Replacing k3k \star 3 with k2+93k\frac{k^2+9}{3k} results in the quadratic equation 2k215k+18=02k^2 - 15k + 18 = 0. The roots are 1.51.5 and 66. Because kk must be strictly greater than 33, the only valid solution is 66.

Adım Adım Çözüm

1
Isolate the custom operation term in the function equation
k3=52k \star 3 = \frac{5}{2}
Setting g(k)=4(k3)7=3g(k) = 4(k \star 3) - 7 = 3 allows us to find the required value of k3k \star 3 by adding 7 to both sides and dividing by 4.
2
Express the custom operation algebraically using its definition
k2+93k=52\frac{k^2 + 9}{3k} = \frac{5}{2}
By definition, xy=x2+y2xyx \star y = \frac{x^2 + y^2}{xy}, so k3=k2+323(k)=k2+93kk \star 3 = \frac{k^2 + 3^2}{3(k)} = \frac{k^2 + 9}{3k}.
3
Form and solve the quadratic equation
k = 1.5 \text{ or } k = 6
Cross-multiplying gives 2(k2+9)=5(3k)2(k^2 + 9) = 5(3k), which simplifies to 2k215k+18=02k^2 - 15k + 18 = 0. Factoring as (2k3)(k6)=0(2k - 3)(k - 6) = 0 yields two roots: k=1.5k = 1.5 and k=6k = 6.
4
Apply the domain constraint
k = 6
The problem specifies that k>3k > 3. Since 1.531.5 \le 3, k=1.5k = 1.5 is rejected, leaving k=6k = 6 as the unique correct answer.

Anahtar Kavram

Custom Binary Symbol Operations and Composite Functions
Soru 233Soru

An agricultural facility uses two automated irrigation systems, System P and System Q, to water a field. System P pumps water at a constant rate of 120120 gallons per hour after requiring an initial setup overhead of 3030 minutes (0.50.5 hours). System Q pumps water at a constant rate of 180180 gallons per hour after requiring an initial setup overhead of 4545 minutes (0.750.75 hours). Both systems begin their setup process at the exact same time and operate continuously until a combined total of 1,6051,605 gallons of water has been pumped. Which of the following statements must be true? Select all such statements.

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Cevap: The total elapsed time from when setup began until the target volume was reached is 66 hours.; System Q pumped 285285 more gallons of water than System P.; The ratio of the volume of water pumped by System P to that pumped by System Q is 44:6344:63.

Cevap

The correct statements are: the total elapsed time from when setup began is 6 hours, System Q pumped 285 more gallons than System P, and the ratio of water pumped by System P to System Q is 44:63.
Solving the combined linear rate model yields a total elapsed time of 6 hours. With this duration, System P operates for 5.5 hours producing 660 gallons, and System Q operates for 5.25 hours producing 945 gallons. This confirms that the total time is 6 hours, System Q produces 285 more gallons than System P (945 - 660 = 285), and the ratio of System P's volume to System Q's volume is 660:945, which simplifies to 44:63.

Adım Adım Çözüm

1
Define the variable for total time and establish time expressions for active pumping.
Let tt be the total elapsed time in hours since both systems began setup (t0.75t \geq 0.75). System P actively pumps for (t0.5)(t - 0.5) hours, and System Q actively pumps for (t0.75)(t - 0.75) hours.
Setup overhead delays the start of pumping, so active pumping duration equals total elapsed time minus setup time.
2
Set up and solve the linear rate equation for combined total volume.
120(t0.5)+180(t0.75)=1605    120t60+180t135=1605    300t195=1605    300t=1800    t=6120(t - 0.5) + 180(t - 0.75) = 1605 \implies 120t - 60 + 180t - 135 = 1605 \implies 300t - 195 = 1605 \implies 300t = 1800 \implies t = 6 hours.
The sum of the volumes produced by both systems must equal the target total of 1,605 gallons.
3
Calculate individual pumping times and volumes produced by each system.
System P: active time =5.5= 5.5 hours, volume =120×5.5=660= 120 \times 5.5 = 660 gallons. System Q: active time =5.25= 5.25 hours, volume =180×5.25=945= 180 \times 5.25 = 945 gallons.
Individual volumes are required to evaluate statements regarding volume differences, percentages, and ratios.
4
Evaluate each given statement against the calculated values.
Elapsed time is 66 hours (True). Volume difference is 945660=285945 - 660 = 285 gallons (True). Active pumping time for P is 5.55.5 hours, not 5.255.25 hours (False). Percentage for Q is 945/160558.88%<60%945 / 1605 \approx 58.88\% < 60\% (False). Ratio P to Q is 660:945=44:63660 : 945 = 44 : 63 (True).
Determines which of the statements must be selected.

Anahtar Kavram

Linear Modeling with Combined Work Rates and Staggered Start Times
Soru 234Soru

In the xyxy-plane, line L1L_1 is given by the equation ax+3y=12ax + 3y = 12, where aa is a constant. Line L2L_2 is perpendicular to line L1L_1 and passes through the point (4,1)(4, -1). If the xx-intercept of line L2L_2 is double its yy-intercept, and both intercepts of line L2L_2 are non-zero, what is the value of aa?

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Cevap: 6-6

Cevap

6-6
Rearranging L1:ax+3y=12L_1: ax + 3y = 12 into slope-intercept form gives y=a3x+4y = -\frac{a}{3}x + 4, yielding a slope of m1=a3m_1 = -\frac{a}{3}. The perpendicular line L2L_2 has a slope of m2=3am_2 = \frac{3}{a}. Using the point (4,1)(4, -1), the equation for L2L_2 is y+1=3a(x4)y + 1 = \frac{3}{a}(x - 4), which simplifies to y=3ax12+aay = \frac{3}{a}x - \frac{12+a}{a}. Setting x=0x = 0 gives the yy-intercept y0=12+aay_0 = -\frac{12+a}{a}, and setting y=0y = 0 gives the xx-intercept x0=12+a3x_0 = \frac{12+a}{3}. Equating x0=2y0x_0 = 2 y_0 yields 12+a3=212+aa\frac{12+a}{3} = -2\frac{12+a}{a}. Canceling the non-zero term (12+a)(12+a) gives 13=2a\frac{1}{3} = -\frac{2}{a}, which leads to a=6a = -6.

Adım Adım Çözüm

1
Determine the slope of line L1L_1 and line L2L_2
Slope of L1L_1 is m1=a3m_1 = -\frac{a}{3}, so the slope of perpendicular line L2L_2 is m2=3am_2 = \frac{3}{a}.
Perpendicular lines have slopes that are negative reciprocals of each other.
2
Write the equation of line L2L_2 using point-slope form
y(1)=3a(x4)    y=3ax12a1=3ax(12+aa)y - (-1) = \frac{3}{a}(x - 4) \implies y = \frac{3}{a}x - \frac{12}{a} - 1 = \frac{3}{a}x - \left(\frac{12 + a}{a}\right).
Line L2L_2 passes through (4,1)(4, -1) with slope m2=3am_2 = \frac{3}{a}.
3
Find the xx-intercept and yy-intercept of line L2L_2
The yy-intercept is y0=12+aay_0 = -\frac{12 + a}{a}. Setting y=0y = 0 gives 0=3ax12+aa    x0=12+a30 = \frac{3}{a}x - \frac{12 + a}{a} \implies x_0 = \frac{12 + a}{3}.
Intercepts occur where x=0x = 0 (for yy-intercept) and y=0y = 0 (for xx-intercept).
4
Set up and solve the given relation x0=2y0x_0 = 2 y_0
12+a3=2(12+aa)\frac{12 + a}{3} = 2 \left( -\frac{12 + a}{a} \right). Since the intercepts are non-zero, 12+a012 + a \neq 0. Dividing both sides by (12+a)(12 + a) gives 13=2a    a=6\frac{1}{3} = -\frac{2}{a} \implies a = -6.
The problem states the xx-intercept is double the yy-intercept.

Anahtar Kavram

Perpendicular Slopes and Line Intercepts
Tahmini Süre:2m 0s
Soru 235Soru

Let f(x)=x2+bx+cf(x) = x^2 + bx + c, where bb and cc are integers. The equation f(x)=0f(x) = 0 has two distinct real roots, α\alpha and β\beta. If α+β=αβ\alpha + \beta = \alpha\beta and c>0c > 0, which of the following statements must be true? Indicate all such statements.

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Cevap: The constant cc is strictly greater than 4.; Both roots α\alpha and β\beta are positive.; The vertex of the parabola y=f(x)y = f(x) lies in Quadrant IV of the xy-plane.

Cevap

The statements asserting that the constant cc is strictly greater than 4, both roots are positive, and the vertex lies in Quadrant IV must all be true.
By Vieta's formulas, α+β=b\alpha + \beta = -b and αβ=c\alpha\beta = c. Equating sum and product gives b=cb = -c. The discriminant Δ=c24c>0\Delta = c^2 - 4c > 0 requires c>4c > 4 because c>0c > 0. Since sum and product of the roots equal c>0c > 0, both roots are positive. The vertex coordinates (c/2,c(c4)/4)(c/2, -c(c-4)/4) have a positive x-value and a negative y-value, placing the vertex in Quadrant IV.

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1
Apply Vieta's formulas and establish the relationship between coefficients
α+β=b\alpha + \beta = -b and αβ=c\alpha\beta = c. Setting them equal gives b=c    b=c-b = c \implies b = -c.
The stem specifies that the sum of the roots equals their product.
2
Analyze the discriminant for distinct real roots
Δ=b24c=(c)24c=c(c4)>0\Delta = b^2 - 4c = (-c)^2 - 4c = c(c - 4) > 0. Since c>0c > 0, c4>0    c>4c - 4 > 0 \implies c > 4.
Two distinct real roots require a strictly positive discriminant.
3
Determine the signs of the roots
α+β=c>0\alpha + \beta = c > 0 and αβ=c>0\alpha\beta = c > 0, implying α>0\alpha > 0 and β>0\beta > 0.
If the sum and product of two real numbers are both positive, both numbers must be positive.
4
Find the location of the parabola's vertex
xv=c2>0x_v = \frac{c}{2} > 0 and yv=c(c4)4<0y_v = -\frac{c(c-4)}{4} < 0, placing the vertex in Quadrant IV.
A point with a positive x-coordinate and negative y-coordinate resides in the fourth quadrant.
5
Evaluate the remaining options regarding bb and αβ|\alpha - \beta|
b=c<4b = -c < -4 (negative), and αβ=2    c=2+22|\alpha - \beta| = 2 \implies c = 2 + 2\sqrt{2}, which is not an integer.
These evaluations disprove the statements that bb is positive and that αβ|\alpha - \beta| can equal 2.

Anahtar Kavram

Quadratic Root Properties and Vieta's Formulas
Soru 236Soru

A laboratory processes two types of chemical samples, Type A and Type B. Processing each Type A sample requires 4040 minutes and costs $30\$30, while processing each Type B sample requires 3030 minutes and costs $50\$50. On a given day, the laboratory spent a total of 2020 hours processing these two types of samples at a total cost of $1,450\$1,450. How many more Type B samples were processed than Type A samples?

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Cevap: 5

Cevap

5 more Type B samples were processed than Type A samples.
The correct answer is 5. By defining xx as the number of Type A samples and yy as the number of Type B samples, we construct the time equation 40x+30y=1,20040x + 30y = 1,200 and cost equation 30x+50y=1,45030x + 50y = 1,450. Solving this system yields x=15x = 15 and y=20y = 20. The difference yx=2015=5y - x = 20 - 15 = 5.

Adım Adım Çözüm

1
Define variables and convert units to maintain consistency.
Let xx be the number of Type A samples and yy be the number of Type B samples. Total time available is 20 hours×60 minutes/hour=1,200 minutes20 \text{ hours} \times 60 \text{ minutes/hour} = 1,200 \text{ minutes}.
Time specifications for individual samples are given in minutes, so total time must also be in minutes.
2
Set up a system of two linear equations representing total time and total cost.
Time equation: 40x+30y=1,200    4x+3y=12040x + 30y = 1,200 \implies 4x + 3y = 120. Cost equation: 30x+50y=1,450    3x+5y=14530x + 50y = 1,450 \implies 3x + 5y = 145.
The total processing time is the sum of time spent on each sample type, and total cost is the sum of costs for each sample type.
3
Solve the system of equations using elimination.
Multiply the time equation by 3: 12x+9y=36012x + 9y = 360. Multiply the cost equation by 4: 12x+20y=58012x + 20y = 580. Subtracting the first from the second gives 11y=220    y=2011y = 220 \implies y = 20. Substitute y=20y = 20 into 4x+3(20)=120    4x=60    x=154x + 3(20) = 120 \implies 4x = 60 \implies x = 15.
Eliminating xx allows direct calculation of yy, which then yields xx.
4
Calculate the difference requested by the problem.
Difference = yx=2015=5y - x = 20 - 15 = 5.
The question specifically asks for how many more Type B samples were processed than Type A samples.

Anahtar Kavram

Formulating and solving systems of linear equations from real-world rate and budget constraints.
Tahmini Süre:1m 45s
Soru 237Soru

For all real numbers xx, the function gg is defined by g(x)=cx+5g(x) = cx + 5, where cc is a constant. The custom operation \diamond is defined for all real numbers aa and bb by ab=g(a+b)g(ab)a \diamond b = g(a+b) - g(a-b). If 31=123 \diamond 1 = 12, what is the value of g(4)g(4)?

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Cevap: 29

Cevap

29
Applying the function definition g(x)=cx+5g(x) = cx + 5 to the custom operation yields ab=[c(a+b)+5][c(ab)+5]=2bca \diamond b = [c(a+b)+5] - [c(a-b)+5] = 2bc. Substituting a=3a=3 and b=1b=1 into 31=123 \diamond 1 = 12 gives 2(1)c=122(1)c = 12, so c=6c = 6. Consequently, g(x)=6x+5g(x) = 6x + 5, and evaluating at x=4x = 4 yields g(4)=6(4)+5=29g(4) = 6(4) + 5 = 29.

Adım Adım Çözüm

1
Substitute (a+b)(a+b) and (ab)(a-b) into the function definition g(x)=cx+5g(x) = cx + 5 to simplify aba \diamond b.
ab=[c(a+b)+5][c(ab)+5]=2bca \diamond b = [c(a+b) + 5] - [c(a-b) + 5] = 2bc.
Applying the definition of the custom binary operation in terms of function gg eliminates the constant term 55.
2
Use the given equality 31=123 \diamond 1 = 12 to determine the constant cc.
2(1)c=12    2c=12    c=62(1)c = 12 \implies 2c = 12 \implies c = 6.
Plugging a=3a=3 and b=1b=1 into 2bc=122bc = 12 yields an equation in terms of cc.
3
Evaluate g(4)g(4) using c=6c = 6.
g(4)=6(4)+5=29g(4) = 6(4) + 5 = 29.
Substituting x=4x = 4 into g(x)=6x+5g(x) = 6x + 5 calculates the required numerical value.

Anahtar Kavram

Functions and Custom Symbol Operations
Tahmini Süre:1m 30s
Soru 238Soru

In the xyxy-plane, line mm has an xx-intercept of 6-6 and a yy-intercept of 33. Line kk is perpendicular to line mm and passes through the point (4,9)(4, 9). What is the xx-intercept of line kk?

Cevabı ve açıklamayı göster

Cevap: 8.5

Cevap

8.5
First, determine the slope of line mm using the given intercepts (6,0)(-6,0) and (0,3)(0,3), yielding 300(6)=12\frac{3-0}{0-(-6)} = \frac{1}{2}. Since line kk is perpendicular to line mm, its slope is the negative reciprocal of 12\frac{1}{2}, which is 2-2. Using the point-slope equation with point (4,9)(4,9), the equation of line kk is y9=2(x4)y - 9 = -2(x - 4), simplifying to y=2x+17y = -2x + 17. Finding the xx-intercept by setting y=0y = 0 yields 0=2x+170 = -2x + 17, giving x=8.5x = 8.5.

Adım Adım Çözüm

1
Calculate the slope of line mm
Slope of line mm is 12\frac{1}{2}
Line mm passes through the points (6,0)(-6,0) and (0,3)(0,3).
2
Determine the slope of perpendicular line kk
Slope of line kk is 2-2
Perpendicular lines have negative reciprocal slopes.
3
Derive the equation of line kk
y=2x+17y = -2x + 17
Use point-slope form with given point (4,9)(4,9) and slope 2-2.
4
Solve for the xx-intercept of line kk
x=8.5x = 8.5
Set y=0y = 0 in the linear equation y=2x+17y = -2x + 17.

Anahtar Kavram

Perpendicular lines, slope calculation from intercepts, and line equations
Soru 239Soru

A commercial bakery uses two automated ovens, Oven X and Oven Y, to bake identical orders of bread. Working alone at its constant rate, Oven X bakes a full order of bread in 88 hours, while Oven Y, working alone at its constant rate, bakes the same order in 1212 hours. Both ovens begin baking a full order together at 8:00 a.m. At 10:00 a.m., Oven X shuts down due to a maintenance alert, and Oven Y continues working alone at its constant rate until the order is completed. How many total hours, from 8:00 a.m. until completion, does it take to finish the order?

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Cevap: 9

Cevap

The total time required from 8:00 a.m. to complete the order is 99 hours.
Working together for 22 hours at a combined rate of 18+112=524\frac{1}{8} + \frac{1}{12} = \frac{5}{24} per hour completes 512\frac{5}{12} of the order. The remaining 712\frac{7}{12} of the order takes Oven Y 77 hours to complete at its rate of 112\frac{1}{12} per hour. Adding the initial 22 hours gives a total time of 99 hours.

Adım Adım Çözüm

1
Determine the individual hourly work rates.
Oven X completes 18\frac{1}{8} of the job per hour, and Oven Y completes 112\frac{1}{12} of the job per hour.
Work rate is the reciprocal of the total time required to complete one full job.
2
Calculate the fraction of the job completed in the first 22 hours.
Combined rate is 18+112=524\frac{1}{8} + \frac{1}{12} = \frac{5}{24} job per hour. In 22 hours, they complete 2×524=5122 \times \frac{5}{24} = \frac{5}{12} of the job.
Both ovens work simultaneously for 22 hours before Oven X stops.
3
Determine the remaining fraction of the job.
1512=7121 - \frac{5}{12} = \frac{7}{12} of the job remains.
The full order represents 11 whole unit of work.
4
Find the additional time required for Oven Y to finish the remaining job alone.
Time=7/121/12=7\text{Time} = \frac{7/12}{1/12} = 7 hours.
Time equals remaining work divided by Oven Y's individual work rate.
5
Calculate the total time elapsed from start to completion.
2+7=92 + 7 = 9 hours.
The total time includes the 22 hours of combined work plus the 77 hours Oven Y worked alone.

Anahtar Kavram

Combined Work Rates and Modeling Staggered Work
Soru 240Soru

A technology company manages data storage across three servers: Server X, Server Y, and Server Z. Initially, the amount of data stored on Server Y is 25%25\% greater than the amount stored on Server X, and Server Z stores 4040 gigabytes less data than Server Y. During a system reorganization, the data on Server X increases by 20%20\%, the data on Server Y decreases by 20%20\%, and the data on Server Z increases by 6060 gigabytes. If the total amount of data stored across all three servers after the reorganization is 10%10\% greater than the total initial amount of data, what was the initial amount of data, in gigabytes, stored on Server X?

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Cevap: 160

Cevap

160 gigabytes
Let xx be the initial storage on Server X in gigabytes. Then Server Y initially stores 1.25x1.25x gigabytes and Server Z stores 1.25x401.25x - 40 gigabytes. The initial total storage is T1=x+1.25x+(1.25x40)=3.5x40T_1 = x + 1.25x + (1.25x - 40) = 3.5x - 40. After reorganization, Server X stores 1.20x1.20x, Server Y stores 0.80(1.25x)=1.00x0.80(1.25x) = 1.00x, and Server Z stores (1.25x40)+60=1.25x+20(1.25x - 40) + 60 = 1.25x + 20. The new total storage is T2=1.20x+1.00x+1.25x+20=3.45x+20T_2 = 1.20x + 1.00x + 1.25x + 20 = 3.45x + 20. Since T2T_2 is 10%10\% greater than T1T_1, we have 3.45x+20=1.10(3.5x40)3.45x + 20 = 1.10(3.5x - 40). Expanding the right side gives 3.45x+20=3.85x443.45x + 20 = 3.85x - 44. Rearranging terms yields 0.40x=640.40x = 64, which simplifies to x=160x = 160 gigabytes.

Adım Adım Çözüm

1
Define variables for the initial storage on each server in terms of the initial storage on Server X, xx.
Server X = xx, Server Y = 1.25x1.25x, Server Z = 1.25x401.25x - 40.
Server Y is 25% greater than Server X (1+0.25=1.251 + 0.25 = 1.25), and Server Z is 40 gigabytes less than Server Y.
2
Sum the initial storage values to find the total initial storage T1T_1.
T1=x+1.25x+(1.25x40)=3.5x40T_1 = x + 1.25x + (1.25x - 40) = 3.5x - 40.
Combining like terms gives the overall starting storage equation.
3
Express the storage on each server after the reorganization in terms of xx.
Server X' = 1.20x1.20x, Server Y' = 0.80(1.25x)=1.00x0.80(1.25x) = 1.00x, Server Z' = (1.25x40)+60=1.25x+20(1.25x - 40) + 60 = 1.25x + 20.
Server X increases by 20%, Server Y decreases by 20% of its initial value, and Server Z gains 60 gigabytes.
4
Sum the updated storage values to find the new total storage T2T_2.
T2=1.20x+1.00x+(1.25x+20)=3.45x+20T_2 = 1.20x + 1.00x + (1.25x + 20) = 3.45x + 20.
Adding the three updated amounts gives the new total expression.
5
Set up and solve the equation representing the 10%10\% overall increase (T2=1.10T1T_2 = 1.10 T_1).
3.45x+20=1.10(3.5x40)    3.45x+20=3.85x44    64=0.40x    x=1603.45x + 20 = 1.10(3.5x - 40) \implies 3.45x + 20 = 3.85x - 44 \implies 64 = 0.40x \implies x = 160.
Solving the linear algebraic model yields the value for initial storage on Server X.

Anahtar Kavram

Linear algebraic modeling of dynamic multi-variable systems involving percentage changes.
Tahmini Süre:2m 30s
ÖncekiSayfa 12 / 18Sonraki
Algebra Alıştırma Soruları — GRE General Test — Sayfa 12 | Examkin