Digital PSAT Math Practice Question 151: Answer and Explanation

Question: 151

Solve for = 18

• A. 24
• B.
• C.
• D. 6

Correct Answer: D

Explanation:

(D) We want to isolate what's inside the parentheses with the goal of eventually isolating x. Let's first get that 6 out of the denominator by multiplying both sides by 6:

To isolate what's inside the parentheses, we have to divide both sides by 12:

Now we can get rid of the parentheses:

To isolate our x-terms, multiply both sides by 2:

Combine the like x-terms:

Because 3x = 18, it follows that x = 6.