ACT Math : Expressions

Study concepts, example questions & explanations for ACT Math

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Example Questions

Example Question #963 : Algebra

If , what is the value of:

Possible Answers:

Correct answer:

Explanation:

Substituting x+y for 5, we get

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

30 - 25 + 1 + 8

= 14

Example Question #62 : Expressions

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?

Possible Answers:

Correct answer:

Explanation:

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).

Example Question #27 : Evaluating Expressions

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

Possible Answers:

(4s + 8)/r

s(4r + 8)

(8 – 4r)/s

(4r + 8)/s

(8 – 4s)/r

Correct answer:

(4r + 8)/s

Explanation:

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

Example Question #965 : Algebra

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

Possible Answers:

(x – 8)(x – 2)

(x + 6)(x – 6)

(x + 6)(x – 4)

(x + 4)(x – 4)

(x + 8)(x + 2)

Correct answer:

(x – 8)(x – 2)

Explanation:

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).

Example Question #964 : Algebra

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

Possible Answers:

Correct answer:

Explanation:

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

Example Question #965 : Algebra

If  is defined by the formula , what is  equivalent to?

Possible Answers:

Correct answer:

Explanation:

The function  is defined by . This means that for whatever value is in the space of the  before the symbol , in our case 2, is inserted into any  in the defined function:

For the value that follows , the  value of 1 in our case, is inserted into any  variable in the defined function.

Then simplify:

 is our correct answer after all the simplification.

Example Question #31 : Evaluating Expressions

A dress that normally costs $80 before tax is on sale for 15% off. After the discount is subtracted, a 7% sale tax is added. What is the final price of the dress?

Possible Answers:

Need more information

Correct answer:

Explanation:

The word problem can be simplified into two steps. First, subtracting the 15% discount:

Second, adding the sales tax to the result from the first step:

The percentage is represented as a decimal by dividing the percentage by 100.

So, for the numbers provided:

New Price = 

Final Price = 

 

Example Question #2463 : Act Math

Evaluate the expression: 

 

for  and 

Possible Answers:

Correct answer:

Explanation:

Plug in the values for the variables and use PEMDAS to dictate the order of the operations. PEMDAS stands for Parentheses, Exponents, Multiplication, Division, Addition, and Subtraction. Using this order of operations we get

  so the first part of the expression is .

Next we deal with the exponents,

.

Then, we deal with the multiplication, 

 

Finally, we plug these simplified values back into the equation and solve,

.

Example Question #2464 : Act Math

Tickets for a circus show cost  each when bought in advance and  each when bought at the door. The circus show's goal is to acquire at least  in ticket sales. The show group sold  opening-night tickets in advance.

What is the minimum number of tickets they need to sell at the door on opening night to reach their goal?

Possible Answers:

Correct answer:

Explanation:

Since  tickets were sold in advance, the group earned a revenue of . In order to reach their goal of , they would still need to earn an extra

Since each ticket costs  at the door, the theatre would need to sell tickets, or  tickets (rounded to the next whole number).

Note: the answer is NOT  tickets, because if  tickets are sold, the revenue would be  , which does not reach the goal of .

Example Question #2465 : Act Math

If , what is the value of ?

Possible Answers:

Correct answer:

Explanation:

Since  this value can be substituted for  in the function.

Here, the denominator becomes , while the numerator becomes .

Hence, 

.

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