PSAT Math Multiple-Choice Question 289: Answer and Explanation

Question: 289

In the equation above, what is the value of y?

• A. 3
• B. 7
• C. 9
• D. 11

Correct Answer: B

Explanation:

B

Difficulty: Medium

Category: Radicals

Strategic Advice: Backsolve by plugging the answer choices in for y to determine which one makes the given equation true.

Getting to the Answer: Simplify the equation by subtracting 4 from both sides to get . Now, check the answer choices, starting with (B) or (C). If the answer you choose is too large or too small, you'll know which direction to go when testing the next choice.

(B): . This is the correct answer.

If you prefer the algebraic approach, here it is:

Again, (B) is the correct answer.