Tüm alıştırma soruları

2789 soru

Soru 81Soru

In urban ecosystems, green roofs offer a sustainable method to mitigate the heat island effect by cooling densely populated areas. By replacing conventional dark asphalt shingles with living vegetation, city planners can successfully lower ambient air temperatures, decrease stormwater runoff, and ________ solar radiation absorption. These ecological installations not only lower energy costs for individual buildings but also enhance local biodiversity by providing habitats for native pollinators.

Which choice completes the text so that it conforms to the conventions of Standard English?

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Cevap: minimize

Cevap

minimize
The correct option is 'minimize'. The sentence presents a list of actions that city planners 'can' perform: 'lower ambient air temperatures,' 'decrease stormwater runoff,' and the blank. Because 'lower' and 'decrease' are base verbs (bare infinitives) following the helper verb 'can', the final element must also be a base verb ('minimize') to maintain parallel structure.

Adım Adım Çözüm

1
Identify the list of items in the sentence and determine the grammatical structure of the established items.
The sentence presents a list of three actions that city planners 'can' take: 'lower ambient air temperatures,' 'decrease stormwater runoff,' and the blank. Both 'lower' and 'decrease' are base verbs (bare infinitives) following the auxiliary verb 'can'.
Parallel structure requires that items in a list or comparison share the same grammatical form.
2
Select the option that matches the established grammatical structure of base verb forms.
The base verb 'minimize' completes the list in a parallel manner ('can lower... decrease... and minimize').
This maintains the grammatical consistency of the list.

Anahtar Kavram

Parallel structure in lists requires all items to have the same grammatical form.
Soru 82Soru

While preparing a presentation on urban sociology, a student takes the following notes:
* In 2024, sociologist Dr. Marcus Vance studied community cohesion across various city neighborhoods.
* Vance measured community cohesion by tracking the annual frequency of neighborhood-organized events.
* Neighborhoods with at least two public parks averaged twelve neighborhood-organized events per year.
* Neighborhoods with fewer than two public parks averaged only four neighborhood-organized events per year.
* Vance concluded that access to public green spaces directly fosters community engagement.

The student wants to support Dr. Vance's conclusion using information from the notes. Which choice most effectively uses information from the given notes to accomplish this goal?

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Cevap: Neighborhoods with at least two public parks averaged twelve events per year compared to just four in neighborhoods with fewer parks, supporting Vance's conclusion that green spaces foster community engagement.

Cevap

The statement comparing the average number of events in neighborhoods with at least two parks to those with fewer parks, linking this data to Vance's conclusion that green spaces foster community engagement.
The correct option effectively uses the data from the notes (the comparison of twelve events in neighborhoods with at least two parks versus four events in neighborhoods with fewer parks) to support Vance's conclusion that green spaces foster community engagement.

Adım Adım Çözüm

1
Identify the goal of the student's presentation.
The goal is to support Dr. Marcus Vance's conclusion that access to public green spaces directly fosters community engagement.
This is the specific claim the prompt requires the student to support.
2
Examine the notes to find evidence that supports this conclusion.
The notes show a contrast between neighborhoods with at least two parks (averaging twelve events per year) and those with fewer than two parks (averaging only four events per year).
This comparative data provides the empirical basis for Vance's conclusion.
3
Evaluate the options to find the one that combines this specific evidence with the conclusion.
The correct choice highlights the comparison in event frequency and directly connects it to Vance's conclusion about green spaces and community engagement.
It fulfills the rhetorical goal using only the provided facts.

Anahtar Kavram

Rhetorical Synthesis: Supporting Claims
Soru 83Soru
y=x28x+cy=2x5\begin{aligned} y &= x^2 - 8x + c \\ y &= 2x - 5 \end{aligned}

In the system of equations above, cc is a constant. If the system has two real solutions, (x1,y1)(x_1, y_1) and (x2,y2)(x_2, y_2), such that the product of the yy-coordinates of the solutions, y1y2y_1 y_2, is equal to 55, what is the value of cc?

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Cevap: 15

Cevap

The value of the constant cc is 1515.
Substituting the expression for yy from the linear equation into the quadratic equation yields the single variable quadratic equation x210x+(c+5)=0x^2 - 10x + (c+5) = 0. Using Vieta's formulas, the sum of the roots is x1+x2=10x_1 + x_2 = 10 and the product of the roots is x1x2=c+5x_1 x_2 = c+5. Substituting these relationships into the expanded product of the yy-coordinates, y1y2=(2x15)(2x25)=4x1x210(x1+x2)+25y_1 y_2 = (2x_1 - 5)(2x_2 - 5) = 4x_1 x_2 - 10(x_1 + x_2) + 25, allows us to set up the equation 5=4(c+5)100+255 = 4(c+5) - 100 + 25. Solving for cc yields 1515. Checking the discriminant of the quadratic equation at c=15c=15 gives 10080=20100 - 80 = 20, which is positive, confirming the existence of two distinct real solutions.

Adım Adım Çözüm

1
Substitute the expression for yy from the second equation into the first equation.
2x5=x28x+c    x210x+(c+5)=02x - 5 = x^2 - 8x + c \implies x^2 - 10x + (c+5) = 0
This substitution reduces the system to a single quadratic equation whose roots, x1x_1 and x2x_2, represent the xx-coordinates of the intersection points.
2
Apply Vieta's formulas to the resulting quadratic equation.
x1+x2=10x_1 + x_2 = 10 and x1x2=c+5x_1 x_2 = c+5
Vieta's formulas state that for a quadratic equation ax2+bx+d=0ax^2 + bx + d = 0, the sum of the roots is ba-\frac{b}{a} and the product of the roots is \frac{d}{a}.
3
Express the product of the yy-coordinates, y1y2y_1 y_2, in terms of x1x_1 and x2x_2 using the linear relationship.
y1y2=(2x15)(2x25)=4x1x210(x1+x2)+25y_1 y_2 = (2x_1 - 5)(2x_2 - 5) = 4x_1 x_2 - 10(x_1 + x_2) + 25
Since both intersection points lie on the line y=2x5y = 2x - 5, we can substitute y1=2x15y_1 = 2x_1 - 5 and y2=2x25y_2 = 2x_2 - 5 and expand.
4
Substitute the Vieta's formulas relations into the product equation and solve for cc.
5=4(c+5)10(10)+25    5=4c+20100+25    5=4c55    60=4c    c=155 = 4(c + 5) - 10(10) + 25 \implies 5 = 4c + 20 - 100 + 25 \implies 5 = 4c - 55 \implies 60 = 4c \implies c = 15
By substituting the known values of (x1+x2)(x_1 + x_2) and (x1x2)(x_1 x_2) and setting the product y1y2y_1 y_2 to 55, we obtain a linear equation in terms of cc that we can solve directly.

Anahtar Kavram

Solving systems of linear-quadratic equations using algebraic substitution and Vieta's formulas.
Soru 84Soru

A landscaping company uses the equation 12x+18y=24012x + 18y = 240 to model the total cost, in dollars, of renting a wood chipper for xx hours and a soil aerator for yy hours. If the wood chipper was rented for 5 more hours than the soil aerator, and the company spent a total of 240240 on these rentals, for how many hours was the soil aerator rented?

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Cevap: 6

Cevap

The soil aerator was rented for 6 hours.
The correct answer is 6. By writing the relationship between the rental hours as x=y+5x = y + 5 and substituting this expression into the cost equation, we obtain 12(y+5)+18y=24012(y + 5) + 18y = 240. Distributing the 12 results in 12y+60+18y=24012y + 60 + 18y = 240. Combining the like terms gives 30y+60=24030y + 60 = 240. Subtracting 60 from both sides of the equation yields 30y=18030y = 180. Dividing both sides by 30 results in y=6y = 6. Therefore, the soil aerator was rented for 6 hours.

Adım Adım Çözüm

1
Express the relationship between the rental hours of the wood chipper (xx) and the soil aerator (yy) as an equation.
x=y+5x = y + 5
The wood chipper was rented for 5 more hours than the soil aerator.
2
Substitute the expression for xx into the cost equation 12x+18y=24012x + 18y = 240.
12(y+5)+18y=24012(y + 5) + 18y = 240
Substitution reduces the equation to a single variable, allowing us to solve for yy.
3
Distribute the 12 and combine like terms.
12y+60+18y=240    30y+60=24012y + 60 + 18y = 240 \implies 30y + 60 = 240
Simplification isolates the variable terms on one side.
4
Isolate yy by subtracting 60 from both sides and then dividing by 30.
30y=180    y=630y = 180 \implies y = 6
This calculation yields the rental hours for the soil aerator.

Anahtar Kavram

Solving a system of linear equations in two variables where one equation represents a budget constraint and the other relates the quantities of the two variables.
Soru 85Soru

Many astronomers believe that the presence of liquid water is the single most important factor in determining a planet's habitability. However, researcher Dr. Elena Rostova argues that a planet’s magnetic field is equally critical. Without a robust magnetic field, solar winds can strip away a planet’s atmosphere, preventing liquid water from ever accumulating on the surface. Thus, Rostova’s team focuses their search on exoplanets that exhibit signs of strong magnetospheres.

Which choice best describes the function of the underlined sentence in the text as a whole?

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Cevap: It explains the process by which a weak magnetic field prevents a planet from maintaining liquid water.

Cevap

It explains the process by which a weak magnetic field prevents a planet from maintaining liquid water.
The correct option correctly identifies that the underlined sentence describes the mechanism (atmosphere stripping by solar winds) that prevents liquid water accumulation when a magnetic field is absent. This explanation supports Rostova's argument that a magnetic field is critical to habitability.

Adım Adım Çözüm

1
Analyze the role of the underlined sentence in context.
The underlined sentence states that without a magnetic field, solar winds strip the atmosphere and prevent water from accumulating.
This helps identify the logical relationship between the underlined sentence and the surrounding sentences.
2
Connect the sentence to the main claim of the passage.
Dr. Rostova claims that a magnetic field is critical; the underlined sentence explains why by showing the consequence of not having one.
This establishes the rhetorical function of the sentence as supporting the researcher's argument.
3
Evaluate the choices to find the one that matches this function.
The option stating that it explains how a weak magnetic field prevents water retention matches the analysis, whereas other options mischaracterize the text or speculate beyond it.
This confirms the correct option.

Anahtar Kavram

Identifying the rhetorical function of a specific sentence within a passage, particularly how it supports a main claim.
Soru 86Soru

A quadratic function gg is defined by g(x)=3(x5)24g(x) = 3(x - 5)^2 - 4. If the graph of y=g(x)y = g(x) in the xyxy-plane is translated 66 units up to produce the graph of y=f(x)y = f(x), what is the yy-coordinate of the vertex of the graph of y=f(x)y = f(x)?

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Cevap: 2

Cevap

The correct answer is 2.
The original function g(x)=3(x5)24g(x) = 3(x - 5)^2 - 4 is in vertex form y=a(xh)2+ky = a(x - h)^2 + k, where the vertex is (h,k)(h, k). Therefore, the vertex of the graph of gg is (5,4)(5, -4). Translating a graph upward by 66 units is represented by adding 66 to the function, so f(x)=g(x)+6f(x) = g(x) + 6. This transformation shifts the vertex from (5,4)(5, -4) to (5,4+6)(5, -4 + 6), which is (5,2)(5, 2). The yy-coordinate of this new vertex is 22.

Adım Adım Çözüm

1
Identify the vertex of the original quadratic function.
The vertex of the graph of g(x)=3(x5)24g(x) = 3(x - 5)^2 - 4 is (5,4)(5, -4).
A quadratic function written in vertex form y=a(xh)2+ky = a(x - h)^2 + k has its vertex at (h,k)(h, k).
2
Determine the vertex of the translated function.
The vertex of the graph of y=f(x)y = f(x) is (5,2)(5, 2).
Translating a graph 66 units up increases the yy-coordinate of all points, including the vertex, by 66.

Anahtar Kavram

Vertex form of a quadratic function and vertical translation of graphs.
Tahmini Süre:45s
Soru 87Soru

A commercial agricultural irrigation system distributes liquid fertilizer from a storage tank. The volume of fertilizer remaining in the tank, VV, in liters, mm minutes after the system is turned on is modeled by the equation:

V=1,80015(m3c)V = 1,800 - 15(m - 3c)

where cc is the number of times the system's nozzles are cleaned during the irrigation process. During each cleaning cycle, the flow of fertilizer is completely paused, and no fertilizer is distributed. Based on the model, what is the duration, in minutes, of a single cleaning cycle?

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Cevap: 3

Cevap

The duration of a single cleaning cycle is 3 minutes.
In the model V=1,80015(m3c)V = 1,800 - 15(m - 3c), the term (m3c)(m - 3c) represents the total time, in minutes, that the irrigation system is actively distributing fertilizer. Since the total elapsed time is mm minutes and the system pauses during cleaning cycles, the term 3c3c represents the total paused time for cc cleanings. Therefore, the duration of a single cleaning cycle is 3cc=3\frac{3c}{c} = 3 minutes.

Adım Adım Çözüm

1
Analyze the structure of the equation to identify the meaning of each term.
The coefficient 15 is the active flow rate in liters per minute, and (m3c)(m - 3c) is the active distribution time in minutes.
To understand how the time variables affect the volume of fertilizer remaining.
2
Relate the total elapsed time to the active time and the paused time.
The total elapsed time is mm minutes, and the active time is m3cm - 3c minutes, meaning the system is paused for a total of 3c3c minutes.
To find the expression for the total duration of all cleaning cycles.
3
Determine the duration of a single cleaning cycle.
Since cc cleaning cycles result in a total pause of 3c3c minutes, each cycle lasts 3cc=3\frac{3c}{c} = 3 minutes.
To calculate the duration of one individual cleaning cycle.

Anahtar Kavram

Interpreting Linear Relationships in Context
Soru 88Soru

In the xyxy-plane, the graph of the quadratic function f(x)=ax2+bx+cf(x) = ax^2 + bx + c, where a>0a > 0, has vertex VV. The graph intersects the xx-axis at points AA and BB. If triangle VABVAB is an equilateral triangle with an area of 12312\sqrt{3}, what is the value of aa?

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Cevap: 12\frac{1}{2}

Cevap

The correct answer is the value 1/2.
The value 1/2 is correct because the area of the equilateral triangle determines its side length to be 434\sqrt{3} and its height to be 66. Since the parabola opens upwards and its base lies on the xx-axis, the vertex is V(h,6)V(h, -6). The two xx-intercepts are symmetric about the axis of symmetry x=hx = h, meaning they are located at h±23h \pm 2\sqrt{3}. Substituting one of these points into the vertex form f(x)=a(xh)26f(x) = a(x-h)^2 - 6 yields 0=12a60 = 12a - 6, which gives a=1/2a = 1/2.

Adım Adım Çözüm

1
Determine the side length and height of the equilateral triangle from the given area.
The side length ss is 434\sqrt{3}, and the height of the triangle is 66.
The area of an equilateral triangle with side length ss is given by the formula Area=s234\text{Area} = \frac{s^2\sqrt{3}}{4}. Setting this equal to 12312\sqrt{3} yields s2=48s^2 = 48, which means s=48=43s = \sqrt{48} = 4\sqrt{3}. The height of the triangle is given by htri=s32=4332=6h_{\text{tri}} = \frac{s\sqrt{3}}{2} = \frac{4\sqrt{3} \cdot \sqrt{3}}{2} = 6.
2
Relate the height and side length of the triangle to the vertex and xx-intercepts of the parabola.
The vertex of the parabola is V(h,6)V(h, -6) and the xx-intercepts are at x=h±23x = h \pm 2\sqrt{3}.
Because a>0a > 0, the parabola opens upwards, meaning the vertex V(h,k)V(h, k) lies below the xx-axis. Since the base of the triangle lies on the xx-axis, the vertical distance from the vertex to the xx-axis is the height of the triangle, so k=6k = -6. The axis of symmetry x=hx = h bisects the base ABAB, so the xx-intercepts are located at a distance of half the side length, s2=23\frac{s}{2} = 2\sqrt{3}, to the left and right of hh.
3
Write the quadratic function in vertex form and substitute one of the xx-intercepts to solve for aa.
a=12a = \frac{1}{2}
The vertex form of the quadratic function is f(x)=a(xh)26f(x) = a(x - h)^2 - 6. Substituting the xx-intercept (h+23,0)(h + 2\sqrt{3}, 0) into this equation gives 0=a(h+23h)260 = a(h + 2\sqrt{3} - h)^2 - 6, which simplifies to 0=a(23)26    12a=6    a=120 = a(2\sqrt{3})^2 - 6 \implies 12a = 6 \implies a = \frac{1}{2}.

Anahtar Kavram

Using the symmetry properties and vertex form of a quadratic function to relate the geometric features of its graph to its algebraic coefficients.

Alternatif Yöntem

Alternatively, you can use the relationship between the roots and coefficients. For any quadratic equation ax2+bx+c=0ax^2 + bx + c = 0 with real roots, the distance between the roots is b24aca\frac{\sqrt{b^2 - 4ac}}{|a|}. Since the triangle is equilateral, the height is 32\frac{\sqrt{3}}{2} times this distance. The vertex is at (b2a,b24ac4a)(-\frac{b}{2a}, -\frac{b^2-4ac}{4a}). Setting the absolute value of the vertex yy-coordinate equal to the height allows you to solve for aa directly when combined with the area formula.
Tahmini Süre:3m 0s
Soru 89Soru

If 8x3=2\frac{8}{x - 3} = 2, what is the value of xx?

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Cevap: 7

Cevap

7
To solve the equation 8x3=2\frac{8}{x - 3} = 2, we clear the denominator by multiplying both sides of the equation by x3x - 3. This gives 8=2(x3)8 = 2(x - 3). Distributing the 22 results in 8=2x68 = 2x - 6. Adding 66 to both sides yields 14=2x14 = 2x. Dividing both sides by 22 gives the solution x=7x = 7.

Adım Adım Çözüm

1
Multiply both sides of the equation by x3x - 3 to eliminate the fraction.
8=2(x3)8 = 2(x - 3)
To clear the denominator and simplify the equation.
2
Distribute the 2 to the terms inside the parentheses.
8=2x68 = 2x - 6
To expand the right-hand side of the equation.
3
Add 6 to both sides of the equation.
14=2x14 = 2x
To isolate the term with the variable xx.
4
Divide both sides by 2 to solve for xx.
x=7x = 7
To find the final value of the variable.

Anahtar Kavram

Solving a rational equation that simplifies to a linear equation by multiplying by the common denominator.
Soru 90Soru

A sample of a radioactive isotope decays such that its mass, in grams, is modeled by the function M(t)=Adt12M(t) = A \cdot d^{\frac{t}{12}}, where tt is the time in hours since the measurement began, and AA and dd are positive constants. The mass of the sample decreases by 75%75\% every 2424 hours. If the mass of the sample is 1515 grams when t=36t = 36, what was the initial mass, in grams, of the sample?

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Cevap: 120

Cevap

The initial mass of the sample was 120 grams.
The correct answer is 120. A decrease of 75%75\% over 24 hours means the mass at t+24t+24 is 0.250.25 times the mass at tt. According to the function, M(t+24)=Ad(t+24)/12=Adt/12d2=M(t)d2M(t+24) = A \cdot d^{(t+24)/12} = A \cdot d^{t/12} \cdot d^2 = M(t) \cdot d^2. Equating the two yields d2=0.25d^2 = 0.25, so d=0.5d = 0.5. Substituting t=36t = 36 and M(36)=15M(36) = 15 gives 15=A(0.5)36/12=A(0.5)3=0.125A15 = A \cdot (0.5)^{36/12} = A \cdot (0.5)^3 = 0.125A. Solving for AA gives A=120A = 120.

Adım Adım Çözüm

1
Relate the 24-hour decay rate to the exponent in the function to set up an equation for dd.
d2=0.25d^2 = 0.25
Every 24 hours (tt increases by 24), the mass decreases by 75%75\%, so it becomes 25%25\% (0.250.25) of its previous value. The exponent increases by 24/12=224/12 = 2, multiplying the mass by d2d^2.
2
Solve for the decay base dd.
d=0.5d = 0.5
Since dd is a positive constant, taking the square root of 0.250.25 gives 0.50.5.
3
Substitute the given mass at t=36t = 36 into the model to solve for the initial mass AA.
A=120A = 120
Plugging t=36t = 36 and M(36)=15M(36) = 15 into M(t)=A(0.5)t/12M(t) = A \cdot (0.5)^{t/12} gives 15=A(0.5)315 = A \cdot (0.5)^3, which simplifies to 15=0.125A15 = 0.125A.

Anahtar Kavram

Interpreting and solving exponential decay functions with fractional exponents

Alternatif Yöntem

Instead of solving for dd first, recognize that 3636 hours is exactly 1.51.5 intervals of 2424 hours. Since the mass is multiplied by 0.250.25 (or 14\frac{1}{4}) every 2424 hours, after 3636 hours it will be multiplied by (14)1.5=(14)3/2=18(\frac{1}{4})^{1.5} = (\frac{1}{4})^{3/2} = \frac{1}{8} of its initial value. Therefore, 15=A18    A=12015 = A \cdot \frac{1}{8} \implies A = 120.
Tahmini Süre:3m 0s
Soru 91Soru

If the expression 3x2bx+10x2\frac{3x^2 - bx + 10}{x - 2} is equivalent to 3xc12x23x - c - \frac{12}{x - 2} for all x2x \neq 2, where bb and cc are positive constants, what is the value of bb?

Cevabı ve açıklamayı göster

Cevap: 17

Cevap

17
Multiplying both sides of the equivalence by x2x - 2 results in 3x2bx+10=(3xc)(x2)123x^2 - bx + 10 = (3x - c)(x - 2) - 12. Expanding the right side gives 3x2(6+c)x+(2c12)3x^2 - (6 + c)x + (2c - 12). By equating the coefficients of corresponding terms, we get 2c12=102c - 12 = 10, which solves to c=11c = 11. Substituting this into the xx-coefficient equivalence b=(6+c)-b = -(6 + c) gives b=6+11=17b = 6 + 11 = 17.

Adım Adım Çözüm

1
Multiply both sides of the expression by the denominator x2x - 2 to equate the numerators.
3x2bx+10=(3xc)(x2)123x^2 - bx + 10 = (3x - c)(x - 2) - 12
Since the rational expressions are equivalent for all x2x \neq 2, their numerators must be equal when written over a common denominator.
2
Expand and simplify the right side of the equation.
3x2bx+10=3x2(6+c)x+(2c12)3x^2 - bx + 10 = 3x^2 - (6 + c)x + (2c - 12)
Expanding (3xc)(x2)(3x - c)(x - 2) yields 3x26xcx+2c3x^2 - 6x - cx + 2c, and subtracting 1212 gives the simplified polynomial expression.
3
Equate the constant terms to solve for cc.
10=2c12c=1110 = 2c - 12 \Rightarrow c = 11
For the polynomials to be equivalent, their constant terms must be equal.
4
Equate the coefficients of the xx terms to solve for bb.
b=6+cb=6+11=17b = 6 + c \Rightarrow b = 6 + 11 = 17
Equating the coefficients of xx gives b=(6+c)-b = -(6 + c), which simplifies to b=6+cb = 6 + c.

Anahtar Kavram

Equivalence of rational and polynomial expressions via coefficient comparison

Alternatif Yöntem

Alternatively, you can evaluate the equivalence at a convenient value of xx. For instance, substituting x=0x = 0 into the expression gives 5=c+6-5 = -c + 6, yielding c=11c = 11. Then, evaluating the equation at another convenient value such as x=1x = 1 allows you to solve for bb directly using the now-known value of cc.
Tahmini Süre:1m 30s
Soru 92Soru

A survey of 140 students in the 9th and 10th grades asked about their preferred after-school activity. The results are summarized in the table below.

GradeSportsArtsTotal
9th Grade402060
10th Grade305080
Total7070140

If a student is selected at random from the 9th-grade students, what is the probability that the selected student preferred sports?

Cevabı ve açıklamayı göster

Cevap: 23\frac{2}{3}

Cevap

23\frac{2}{3}
The correct answer is 23\frac{2}{3}. The question asks for the probability that a student preferred sports, given that the student is in the 9th grade. This means we only consider the 60 students in the 9th grade. Of those 60 students, 40 preferred sports. Therefore, the probability is 4060\frac{40}{60}, which simplifies to 23\frac{2}{3}.

Adım Adım Çözüm

1
Identify the group of interest from which the student is selected.
The selection is made from the 9th-grade students, so the denominator for the probability is the total number of 9th-grade students, which is 6060.
The problem states: 'If a student is selected at random from the 9th-grade students,' establishing this as a conditional probability where the sample space is restricted to 9th graders.
2
Identify the number of students within this group who satisfy the target condition.
The number of 9th-grade students who preferred sports is 4040.
We look at the intersection of the '9th Grade' row and the 'Sports' column in the table.
3
Calculate the probability by dividing the number of target outcomes by the total outcomes in the conditional sample space, and simplify the fraction.
The probability is 4060\frac{40}{60}, which simplifies to 23\frac{2}{3}.
Dividing both the numerator and the denominator by their greatest common divisor, 20, gives the simplified probability.

Anahtar Kavram

Calculating conditional probability from a two-way frequency table by restricting the sample space to a specific row or column.
Soru 93Soru
What is the set of all real solutions to the equation below?
3x+10=x+2\sqrt{3x+10} = x+2
Cevabı ve açıklamayı göster

Cevap: {2}\{2\}

Cevap

The set containing only 2
The correct answer is the set containing only 2. Squaring both sides of the equation yields 3x+10=x2+4x+43x + 10 = x^2 + 4x + 4. Rearranging the terms to set the equation to zero gives x2+x6=0x^2 + x - 6 = 0. Factoring the quadratic expression gives (x+3)(x2)=0(x + 3)(x - 2) = 0, indicating potential solutions of x=3x = -3 and x=2x = 2. Substituting x=2x = 2 back into the original equation gives 16=4\sqrt{16} = 4, which is valid. Substituting x=3x = -3 back into the original equation gives 1=1\sqrt{1} = -1, which is invalid because the principal square root is non-negative. Thus, x=3x = -3 is extraneous and must be discarded.

Adım Adım Çözüm

1
Square both sides of the equation to eliminate the radical.
3x+10=(x+2)23x + 10 = (x + 2)^2, which expands to 3x+10=x2+4x+43x + 10 = x^2 + 4x + 4.
Squaring both sides is the standard algebraic method to isolate the term under a square root.
2
Move all terms to one side to form a quadratic equation equal to zero.
x2+x6=0x^2 + x - 6 = 0.
Setting the quadratic expression to zero allows us to solve it by factoring.
3
Factor the quadratic equation.
(x+3)(x2)=0(x + 3)(x - 2) = 0, which gives the potential solutions x=3x = -3 and x=2x = 2.
Finding the factors helps us determine the roots of the equation.
4
Substitute both potential solutions back into the original equation to check for extraneous solutions.
For x=2x = 2: 3(2)+10=16=4\sqrt{3(2)+10} = \sqrt{16} = 4 and 2+2=42+2 = 4, which is true. For x=3x = -3: 3(3)+10=1=1\sqrt{3(-3)+10} = \sqrt{1} = 1 and 3+2=1-3+2 = -1, which is false.
Squaring both sides of an equation can introduce extraneous solutions that do not satisfy the original equation.

Anahtar Kavram

Identifying extraneous solutions in radical equations
Tahmini Süre:1m 30s
Soru 94Soru

If x>2x > 2 and satisfies the equation

x8x22x=54x2x - \frac{8}{x^2 - 2x} = 5 - \frac{4}{x - 2}

what is the value of xx?

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Cevap: 4

Cevap

The correct answer is 4.
To solve the rational equation, we first determine the domain restrictions: x0x \neq 0 and x2x \neq 2. We then clear the denominators by multiplying the entire equation by the least common denominator x(x2)x(x - 2), which simplifies the equation to the cubic form x37x2+14x8=0x^3 - 7x^2 + 14x - 8 = 0. Factoring the cubic polynomial yields (x1)(x2)(x4)=0(x - 1)(x - 2)(x - 4) = 0. The potential solutions are x=1x = 1, x=2x = 2, and x=4x = 4. Since x=2x = 2 is an extraneous solution and the constraint requires x>2x > 2, x=4x = 4 is the only valid solution.

Adım Adım Çözüm

1
Determine the domain restrictions of the rational terms in the equation.
x0x \neq 0 and x2x \neq 2
Division by zero is undefined, so the denominators x(x2)x(x-2) and x2x-2 cannot be zero.
2
Multiply the entire equation by the least common denominator x(x2)x(x - 2) to eliminate the fractions.
x2(x2)8=5x(x2)4xx^2(x - 2) - 8 = 5x(x - 2) - 4x
Multiplying by the common denominator converts the rational equation into an equivalent polynomial equation within the defined domain.
3
Expand the terms and collect them on one side to form a standard polynomial equation.
x37x2+14x8=0x^3 - 7x^2 + 14x - 8 = 0
Simplifying the expressions allows us to find the roots of the polynomial.
4
Factor the cubic polynomial using the rational root theorem or synthetic division.
(x1)(x2)(x4)=0(x - 1)(x - 2)(x - 4) = 0
Since x=1x = 1 makes the polynomial zero, we factor out (x1)(x-1) to get the remaining quadratic factor x26x+8x^2 - 6x + 8, which factors into (x2)(x4)(x - 2)(x - 4).
5
Identify the valid solution based on the domain restriction and the given inequality constraint.
x=4x = 4
The value x=2x = 2 is extraneous because it makes the original equation undefined. The value x=1x = 1 is rejected because the problem specifies x>2x > 2.

Anahtar Kavram

Solving rational equations by clearing denominators, factoring polynomials, identifying extraneous solutions, and applying inequality constraints.
Soru 95Soru
What is the value of the real solution to the equation below?
3x2x+3=1\sqrt{3x - 2} - \sqrt{x + 3} = 1
Cevabı ve açıklamayı göster

Cevap: 6

Cevap

The only real solution to the equation is 6.
Substituting x=6x = 6 into the original equation yields 3(6)26+3=169=43=1\sqrt{3(6) - 2} - \sqrt{6 + 3} = \sqrt{16} - \sqrt{9} = 4 - 3 = 1, which is a true statement. Therefore, the only real solution is 6.

Adım Adım Çözüm

1
Isolate one of the radical terms
3x2=x+3+1\sqrt{3x - 2} = \sqrt{x + 3} + 1
Preparing the equation to square both sides.
2
Square both sides of the equation
3x2=x+4+2x+33x - 2 = x + 4 + 2\sqrt{x + 3}
Eliminating one of the square root radicals.
3
Isolate the remaining radical term and simplify
x3=x+3x - 3 = \sqrt{x + 3}
Simplifying the equation by isolating the second radical and dividing both sides by 2.
4
Square both sides again to eliminate the second radical
x26x+9=x+3x^2 - 6x + 9 = x + 3
Converting the radical equation into a polynomial equation.
5
Write in standard quadratic form and factor
(x6)(x1)=0(x - 6)(x - 1) = 0
Setting the quadratic equation to zero and factoring to find potential solutions.
6
Verify solutions in the original equation to check for extraneous solutions
x=6x = 6 is valid; x=1x = 1 is extraneous
Squaring both sides of an equation can introduce extraneous solutions that do not satisfy the original equation.

Anahtar Kavram

Solving equations containing radical expressions and identifying extraneous solutions.
Tahmini Süre:2m 30s
Soru 96Soru

A transit agency surveyed a sample of 160 commuters about their primary mode of transportation and whether they travel during peak commuting hours. The results are summarized in the table below.

Commute ModePeak HoursOff-Peak HoursTotal
Bus354580
Train552580
Total9070160

If a commuter who travels during peak hours is selected at random from those surveyed, what is the probability that the commuter's primary mode of transportation is the train?

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Cevap: 1118\frac{11}{18}

Cevap

The probability that the commuter's primary mode of transportation is the train, given they travel during peak hours, is 1118\frac{11}{18}.
The correct answer is 1118\frac{11}{18}. To find the probability that a selected commuter's primary mode of transportation is the train, given that they travel during peak hours, we must look only at the column representing peak-hour commuters. The total number of peak-hour commuters is 35+55=9035 + 55 = 90. Among these commuters, the number whose primary mode of transportation is the train is 5555. Therefore, the probability is 5590\frac{55}{90}, which simplifies to 1118\frac{11}{18}.

Adım Adım Çözüm

1
Identify the total number of commuters who meet the condition of traveling during peak hours.
The total number of peak-hour commuters is 9090.
The question asks for the probability given that the commuter travels during peak hours, restricting our sample space to this column total.
2
Identify the number of commuters in the peak hours group whose primary mode of transportation is the train.
There are 5555 commuters who travel by train during peak hours.
This represents the favorable outcomes within our restricted sample space.
3
Calculate the conditional probability by dividing the number of favorable outcomes by the size of the restricted sample space.
5590=1118\frac{55}{90} = \frac{11}{18}
Probability is the ratio of favorable outcomes to the total possible outcomes under the given condition.

Anahtar Kavram

Conditional Probability from a Two-Way Table
Soru 97Soru

In 2024, a city recycled a certain number of tons of plastic. In 2025, the number of tons of plastic recycled was 15%15\% greater than the number of tons recycled in 2024. In 2026, the number of tons of plastic recycled was 20%20\% less than the number of tons recycled in 2025. If the city recycled 5,5205,520 tons of plastic in 2026, how many tons of plastic did the city recycle in 2024?

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Cevap: 6000

Cevap

The city recycled 6,0006,000 tons of plastic in 2024.
To find the number of tons of plastic recycled in 2024, we must work backward from the 2026 value of 5,520 tons. Let xx represent the tons recycled in 2025. Since the 2026 value represents a 20%20\% decrease from 2025, we have 0.80x=5,5200.80x = 5,520, which simplifies to x=6,900x = 6,900 tons. Next, let yy represent the tons recycled in 2024. Since the 2025 value represents a 15%15\% increase from 2024, we have 1.15y=6,9001.15y = 6,900. Solving for yy yields y=6,9001.15=6,000y = \frac{6,900}{1.15} = 6,000 tons.

Adım Adım Çözüm

1
Set up an equation to find the amount of plastic recycled in 2025 using the 2026 amount of 5,520 tons.
The amount of plastic recycled in 2025 was 6,9006,900 tons.
The 2026 amount is a 20%20\% decrease from the 2025 amount, so 5,5205,520 is equal to 80%80\% of the 2025 amount. Solving 0.80x=5,5200.80x = 5,520 gives x=6,900x = 6,900.
2
Set up an equation to find the amount of plastic recycled in 2024 using the 2025 amount of 6,900 tons.
The amount of plastic recycled in 2024 was 6,0006,000 tons.
The 2025 amount is a 15%15\% increase from the 2024 amount, so 6,9006,900 is equal to 115%115\% of the 2024 amount. Solving 1.15y=6,9001.15y = 6,900 gives y=6,000y = 6,000.

Anahtar Kavram

Working backward through multiple sequential percentage changes.
Soru 98Soru

The graph of the function y=f(x)y = f(x) in the xyxy-plane passes through the point (3,4)(3, -4). If the function gg is defined by g(x)=f(x+2)1g(x) = f(x + 2) - 1, which of the following points must lie on the graph of y=g(x)y = g(x)?

Cevabı ve açıklamayı göster

Cevap: (1,5)(1, -5)

Cevap

(1,5)(1, -5)
The correct answer is the point (1,5)(1, -5). Since the point (3,4)(3, -4) lies on the graph of ff, we know that f(3)=4f(3) = -4. For the function g(x)=f(x+2)1g(x) = f(x + 2) - 1, substituting x=1x = 1 gives g(1)=f(1+2)1=f(3)1g(1) = f(1 + 2) - 1 = f(3) - 1. Substituting 4-4 for f(3)f(3) yields g(1)=41=5g(1) = -4 - 1 = -5. Thus, the point (1,5)(1, -5) must lie on the graph of gg.

Adım Adım Çözüm

1
Identify the given function value from the point on the graph of ff.
Since the graph of y=f(x)y = f(x) passes through (3,4)(3, -4), we have f(3)=4f(3) = -4.
Any point (x,y)(x, y) on the graph of a function satisfies the equation y=f(x)y = f(x).
2
Determine the input variable xx for the function g(x)=f(x+2)1g(x) = f(x + 2) - 1 that corresponds to the known input of 33 for ff.
Set the argument of ff in g(x)g(x) equal to 33: x+2=3x + 2 = 3, which simplifies to x=1x = 1.
This allows us to substitute the known value f(3)f(3) into the expression for g(x)g(x).
3
Evaluate g(1)g(1) using the value of f(3)f(3).
g(1)=f(1+2)1=f(3)1=41=5g(1) = f(1 + 2) - 1 = f(3) - 1 = -4 - 1 = -5.
Substituting f(3)=4f(3) = -4 into the simplified expression gives the output value of gg at x=1x = 1.
4
State the resulting point on the graph of y=g(x)y = g(x).
The point is (1,5)(1, -5).
An input of x=1x = 1 yields an output of y=5y = -5 for the function gg.

Anahtar Kavram

Function transformations and their effects on individual coordinate points.
Soru 99Soru

A pharmaceutical company produces two strengths of a certain medication, Strength P and Strength Q, by mixing an active ingredient with a liquid base. In Strength P, the ratio of the volume of the active ingredient to the volume of the liquid base is 22 to 55. In Strength Q, the ratio of the volume of the active ingredient to the volume of the liquid base is 33 to 88. A technician prepares a batch of Strength P and a batch of Strength Q such that the volume of the liquid base used in the batch of Strength P is equal to the volume of the liquid base used in the batch of Strength Q. If the total volume of the active ingredient used in both batches combined is 6262 liters, what is the total volume of the liquid base, in liters, used in both batches combined?

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Cevap: 160

Cevap

The total volume of the liquid base used in both batches combined is 160 liters.
The total volume of the liquid base used in both batches combined is 160 liters. To find this, let the volume of the liquid base in each batch be LL liters. The volume of the active ingredient in Strength P is 25L\frac{2}{5}L liters, and the volume of the active ingredient in Strength Q is 38L\frac{3}{8}L liters. The sum of the active ingredients is 25L+38L=62\frac{2}{5}L + \frac{3}{8}L = 62 liters. Finding a common denominator gives 1640L+1540L=62\frac{16}{40}L + \frac{15}{40}L = 62, which simplifies to 3140L=62\frac{31}{40}L = 62. Solving for LL yields L=62×4031=80L = 62 \times \frac{40}{31} = 80 liters. Since both batches contain equal volumes of liquid base, the combined total volume of the liquid base is 2L=2×80=1602L = 2 \times 80 = 160 liters.

Adım Adım Çözüm

1
Represent the volumes of the ingredients in terms of a single variable.
Let the volume of the liquid base used in each batch be 40x40x liters, where 40 is chosen as the least common multiple of 5 and 8. The volume of the active ingredient in Strength P is 25×40x=16x\frac{2}{5} \times 40x = 16x liters, and the volume of the active ingredient in Strength Q is 38×40x=15x\frac{3}{8} \times 40x = 15x liters.
This establishes a common algebraic scale for both mixtures, utilizing the fact that the volume of the liquid base is identical in both batches.
2
Formulate an equation using the total volume of the active ingredient.
16x+15x=6216x + 15x = 62, which simplifies to 31x=6231x = 62.
The problem states that the combined volume of the active ingredient from both batches is 62 liters.
3
Solve for the variable xx.
x=2x = 2
Dividing both sides of the equation by 31 yields the scaling factor.
4
Calculate the total volume of the liquid base used in both batches combined.
Total liquid base = 40x+40x=80x=80(2)=16040x + 40x = 80x = 80(2) = 160 liters.
Since each batch uses 40x40x liters of liquid base, the total volume for both batches is the sum of their individual base volumes, which is 80x80x liters.

Anahtar Kavram

Solving ratio and proportion problems with a shared quantity
Tahmini Süre:2m 30s
Soru 100Soru

In right triangle PQRPQR, the measure of angle QQ is 9090^\circ. If tan(P)=43\tan(P) = \frac{4}{3}, what is the value of sin(P)\sin(P)?

Cevabı ve açıklamayı göster

Cevap: 45\frac{4}{5}

Cevap

45\frac{4}{5}
The tangent of an angle in a right triangle is defined as the ratio of the length of the opposite side to the length of the adjacent side. Given that tan(P)=43\tan(P) = \frac{4}{3}, we can set the length of the side opposite to angle P as 44 and the adjacent side as 33. Using the Pythagorean theorem, the hypotenuse is 32+42=5\sqrt{3^2 + 4^2} = 5. Since the sine of an angle is the ratio of the opposite side to the hypotenuse, sin(P)=45\sin(P) = \frac{4}{5}.

Adım Adım Çözüm

1
Identify the relationship between the tangent ratio and the sides of the right triangle.
The tangent of angle P is defined as the opposite side divided by the adjacent side. Since tan(P)=43\tan(P) = \frac{4}{3}, we can set the opposite side to 44 and the adjacent side to 33.
This allows us to establish the relative lengths of the sides of the right triangle.
2
Calculate the length of the hypotenuse using the Pythagorean theorem.
The hypotenuse is 32+42=25=5\sqrt{3^2 + 4^2} = \sqrt{25} = 5.
The hypotenuse is required to calculate the sine ratio.
3
Determine the sine of angle P.
The sine of angle P is defined as the opposite side divided by the hypotenuse, which is 45\frac{4}{5}.
This yields the final requested trigonometric ratio.

Anahtar Kavram

Using basic trigonometric ratios (SOH CAH TOA) and the Pythagorean theorem to evaluate trigonometric ratios in a right triangle.
Tahmini Süre:45s
ÖncekiSayfa 5 / 140Sonraki
Tüm alıştırma soruları — SAT | Examkin