PSAT Math Multiple-Choice Question 621: Answer and Explanation

Question: 621

If , what is the range of x?

• A. x > -7
• B.
• C. x < -7
• D. x > 7

Correct Answer: C

Explanation:

(C) Inequalities can be solved just like equations. The only difference is you must remember to flip the inequality sign if you multiply or divide by a negative number.

The first step is to get rid of the denominator by multiplying both sides by 5:

-2x - 4 > 10

Add 4 to both sides:

-2x > 14

Divide both sides by -2 to solve for x. Since we are dividing by a negative number, we need to flip the inequality as follows:

x < -7

The answer is choice (C).