PSAT Math Multiple-Choice Question 237: Answer and Explanation

Question: 237

Which of the following are solutions to the quadratic equation (x + 3)² = 16?

• A. x = -19 and x = 13
• B. x = -7 and x = 1
• C. x = -1 and x = 1
• D. x = -1 and x = 7

Correct Answer: B

Explanation:

B

Difficulty: Medium

Category: Passport to Advanced Math/Quadratics

Getting to the Answer: Notice the structure of the equation. The expression on the left side of the equation is the square of a quantity, so start by taking the square root of both sides. After taking the square roots, solve the resulting equations. Remember, 4² = 16 and (- 4)² = 16, so there will be two equations to solve:

Choice (B) is correct.