PSAT Math Multiple-Choice Question 450: Answer and Explanation

Question: 450

Which of the following are roots for x² + 10x - 8 = 0?

• A.
• B.
• C.
• D.

Correct Answer: B

Explanation:

B

Difficulty: Medium

Getting to the Answer: Since the first term has a constant of 1, completing the square can be used right away. Make sure to move the constant term to the right side of the equation before dividing the x term by 2 and squaring:

Therefore, (B) is correct.