ACT Math : Inequalities

Study concepts, example questions & explanations for ACT Math

varsity tutors app store varsity tutors android store varsity tutors amazon store varsity tutors ibooks store

Example Questions

← Previous 1 3 4 5

Example Question #1 : How To Find The Solution To An Inequality With Subtraction

Given that x = 2 and y = 4, how much less is the value of  2x2 –  2y than the value of  2y2 –  2x ?

Possible Answers:

12

52

2

28

Correct answer:

28

Explanation:

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

2(22) – 2(4) = 8 – 8 = 0

2(42) – 2(2) = 32 – 4 = 28

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

28 – 0 = 28

Example Question #2 : Inequalities

Solve

Possible Answers:

Correct answer:

Explanation:

Absolute value problems are broken into two inequalities:   and .  Each inequality is solved separately to get  and .  Graphing each inequality shows that the correct answer is .

Example Question #3 : Inequalities

Which of the following inequalities defines the solution set to  ?

Possible Answers:

Correct answer:

Explanation:

First, move the s to one side.

Subtract by 1

Divide both sides by 7.

Example Question #10 : Inequalities

The cost, in cents, of manufacturing \dpi{100} \small x pencils is \dpi{100} \small 1200+20x. The pencils sell for 50 cents each. What number of pencils would need to be sold so that the revenue received is at least equal to the manufacturing cost? 

Possible Answers:

\dpi{100} \small 36

\dpi{100} \small 30

\dpi{100} \small 27

\dpi{100} \small 40

\dpi{100} \small 33

Correct answer:

\dpi{100} \small 40

Explanation:

If each pencil sells at 50 cents, \dpi{100} \small x pencils will sell at \dpi{100} \small 50x. The smallest value of \dpi{100} \small x such that

 \dpi{100} \small 50x\geq 1200+20x

\dpi{100} \small x\geq 40

Example Question #4 : Inequalities

Solve the following inequality:

Possible Answers:

Correct answer:

Explanation:

To solve an inequality with subtraction, simply solve it is as an equation.

The goal is to isolate the variable on one side with all other constants on the other side. Perform the opposite operation to manipulate the inequality.

In this case add two to each side.

Example Question #5 : Inequalities

Solve the following inequality:

Possible Answers:

Correct answer:

Explanation:

To solve, simply treat it as an equation.

This means you want to isolate the variable on one side and move all other constants to the other side through opposite operation manipulation.

Remember, you only flip the inequality sign if you multiply or divide by a negative number.

Thus,

Example Question #6 : Inequalities

Solve |x – 5| ≤ 1

Possible Answers:

x ≤ 4 or x ≥ 6

-1 ≤ x ≤ 1

None of the answers are correct

0 ≤ x ≤ 1

4 ≤ x ≤ 6

Correct answer:

4 ≤ x ≤ 6

Explanation:

Absolute values have two answers:  a positive one and a negative one.  Therefore,

-1 ≤ x – 5≤ 1 and solve by adding 5 to all sides to get 4 ≤ x ≤ 6.

Example Question #1 : Inequalities

Solve

Possible Answers:

All real numbers

No solutions

Correct answer:

Explanation:

Absolute value is the distance from the origin and is always positive.

So we need to solve  and  which becomes a bounded solution.

Adding 3 to both sides of the inequality gives  and  or in simplified form

Example Question #8 : Inequalities

Given the inequality  which of the following is correct?

Possible Answers:

 or 

 or 

 or 

Correct answer:

 or 

Explanation:

First separate the inequality   into two equations.

 

Solve the first inequality. 

 

 

Solve the second inequality.

 

Thus,   or .

Example Question #1 : Inequalities

What values of x make the following statement true?

|x – 3| < 9

Possible Answers:

–12 < x < 6

x < 12

6 < x < 12

–3 < x < 9

–6 < x < 12

Correct answer:

–6 < x < 12

Explanation:

Solve the inequality by adding 3 to both sides to get x < 12.  Since it is absolute value, x – 3 > –9 must also be solved by adding 3 to both sides so: x > –6 so combined.

← Previous 1 3 4 5
Learning Tools by Varsity Tutors