PSAT Math Multiple-Choice Question 506: Answer and Explanation

Question: 506

Which if the following is a solution to the equation

(x + 8) = 56?

• A. The equation has no solution.
• B. 24
• C. 32
• D. 40

Correct Answer: B

Explanation:

B

The question asks for a solution to an equation, which is a value for the variable that will make the equation true. Since the question asks for a specific value and the answers contain numbers in increasing order, plug in the answers. Begin by labeling the answers as "x" and start with (C), 32, which is the middle of the numerical answers. The equation becomes , which simplifies to . Use a calculator to multiply the left side of the equation to get 70 = 56. This is not true, so eliminate (C). A smaller number is needed, so check 24, the value in (B). The equation becomes , which simplifies to . Use a calculator to multiply the left side of the equation to get 56 = 56. This is true, so stop here. The correct answer is (B).