Evaluating Expressions - ACT Math

Card 0 of 20

Question

Given that x = 2 and y = 3, how much less is the value of 3_x_2 – 2_y_ than the value of 3_y_2 – 2_x_?

Answer

First, we solve each expression by plugging in the given values for x and y:

3(22) – 2(3) = 12 – 6 = 6

3(32) – 2(2) = 27 – 4 = 23

Then we find the difference between the first and second expressions’ values:

23 – 6 = 17

Compare your answer with the correct one above

Question

Evaluate 4x2 + 6x – 17, when x = 3.

Answer

Plug in 3 for x, giving you 36 + 18 – 17, which equals 37.

Compare your answer with the correct one above

Question

John has a motorcycle. He drives it to the store, which is 30 miles away. It takes him 30 minutes to drive there and 60 minutes to drive back, due to traffic. What was his average speed roundtrip in miles per hour?

Answer

The whole trip is 60 miles, and it takes 90 minutes, which is 1.5 hours.

Miles per hour is 60/1.5 = 40 mph

Compare your answer with the correct one above

Question

If (xy/2) – 3_w_ = –9, what is the value of w in terms of x and y?

Answer

–3_w_ = –9 – (xy/2)

w = 3 + (xy/6)

Compare your answer with the correct one above

Question

Evaluate 5_x_2 + 16_x_ + 7 when x = 7

Answer

Plug in 7 for x and you get 5(49) + 16(7) + 7 = 364

Compare your answer with the correct one above

Question

If x = y – 3, then (y – x)3 =

Answer

Solve for equation for y – x = 3. Then, plug in 3 into (y – x)3 = 27.

Compare your answer with the correct one above

Question

If , what is the value of:

Answer

Substituting x+y for 5, we get

6(5) - 52 + (1/5)(5) + 8

30 - 25 + 1 + 8

= 14

Compare your answer with the correct one above

Question

What is the value of z that satisfies the equation: 10(z 6) = 8z + 4

Answer

Distribute: 10z 60 = 8z + 4

Move all like terms together: 2z = 64

Solve: z = 32

Compare your answer with the correct one above

Question

If , then which of the following is an expression for in terms of and ?

Answer

Divide both sides by , giving you

.

Compare your answer with the correct one above

Question

A company rents cars for a rental fee of $37.00 per day, with an additional charge of $0.45 per mile driven. Which of the following expressions represents the cost, in dollars, of renting the car for 2 days and driving it m miles?

Answer

To determine cost we add the initial rental fee of $37, times two days giving us $74 plus the mileage rate, 0.45, times the number of miles. Giving an equation of 0.45m+74.

Compare your answer with the correct one above

Question

Sally is ordering snacks for her class trip. She needs 85 cookies. The cookies come in cases of 6 boxes, with 7 cookies in each box. Sally can't order a partial box. What is the smallest number of cases she should order?

Answer

We first determine how many cookies are in each box. There are 7 cookies in a box, multiplied by 6 boxes, making 42 cookies in a case. We then divide the total number of cookies she needs, 85, by the number in each case, 42, giving us 2 with a remainder. This means Sally must order 3 cases of cookies.

Compare your answer with the correct one above

Question

Find the value of where:

Answer

This problem requires utilization of the opposite operations to both sides principle.

Adding +2 to both sides yields

Subtracting 2y from both sides yields

Compare your answer with the correct one above

Question

When graphed in the (x,y) coordinate plane, at what point do the lines -2x + 4y = 5 and y = -2 intersect?

Answer

Plugging in y=-2 in the second equation, gives x=-13/2. This is the point where the graphs intersect.

Compare your answer with the correct one above

Question

The length in cm of a plastic container is 5cm less than triple its width. Which of the following equations is an accurate description of the length, l, as a function of the width, w?

Answer

This problem requires the development of an equation. We are told that the length is 5cm less than 3 times its width. So we should set up an equation that describes this situation. The equation l = 3w – 5 demonstrates how the length is 5 cm less than 3 times the width of the container.

Compare your answer with the correct one above

Question

A batting average is determined by calculating the amount of hits a batter accumulates in the amount of at-bats that they have had in a season. However when a batter walks the at-bat is not counted in the calculation of the batter's batting average. Walks also have no effect on a batter's hit count.

Let:

Total at-bats, including times a batter has walked = a

Number of hits = b

Number of walks = c

What is an appropriate expression for the calculation of a hitter's batting average?

Answer

To conform to the way in which a batting average is calculated the equation must be set up so that the amount of hits a batter has accumulated is divided by the amount of at-bats the batter has had, without including at-bats that have resulted in a walk. So the equation should be (hits)/((at-bats) – (walks)), this is acheved by b/(a – c).

Compare your answer with the correct one above

Question

Which of the following is equal (10 – 6)2 if x = 10?

Answer

First, you set up and solve the original equation. Set up (10 – 6)2, then solve it, giving you 16. We can then plug in 10 for x in the answer choices until you find the choice that always gives you 16, which is (x – 8)(x – 2).

Compare your answer with the correct one above

Question

If st – 4_r_ = 8, what is the value of t in terms of r and s?

Answer

We rearrange the equation st – 4r=8 by adding 4r to the right side; then divide by s → t = (4r + 8)/s

Compare your answer with the correct one above

Question

The expression x(9 + x)(x – 2) = 4 is a polynomial of which degree?

Answer

The highest power this polynomial can achieve is 3.

Compare your answer with the correct one above

Question

If 4x+6y=8 , then what is the value of 3(2x + 3y) ?

Answer

The value of 3(2x + 3y) is

Note that 2x + 3y = \frac{1}{2}(4x + 6y) , so 2x + 3y must equal \frac{1}{2}(8) , which is

Since 2x + 3y = 4, we can see that 3(2x + 3y) = 12

Compare your answer with the correct one above

Question

Let \dpi{100} \small a&hash;b=(2a-b)^{2} for all integers \dpi{100} \small a and \dpi{100} \small b. Which of the following is the value of \dpi{100} \small -2&hash;5?

Answer

In order to solve the expression, replace \dpi{100} \small a with \dpi{100} \small -2 and \dpi{100} \small b with \dpi{100} \small 5 in the definition given:

\dpi{100} \small a&hash;b=(2(-2) -5)^{2}

\dpi{100} \small a&hash;b=(-4 -5)^{2}

\dpi{100} \small a&hash;b=(-9)^{2}

\dpi{100} \small a&hash;b=81

Compare your answer with the correct one above

Tap the card to reveal the answer