# SAT Math Multiple Choice Practice Question 197: Answer and Explanation

### Next steps

- Use your browser's back button to return to your test results.
- Do another SAT math multiple choice practice tests.

**Question: 197**

**21.** If (x + 1)2 = 64, then x could be

A. -8

B. -7

C. 7

D. 8

E. 9

**Correct Answer:** C

**Explanation:**

C. You know that when you square x + 1, you get 64, so x + 1 must equal 8 or -8. Set up two equations: x + 1 = 8 and x + 1 = -8. Solving those equations for x, you get x = 7 and x = -9. Because -9 is not one of the solutions offered, (C) must be the right choice.

If you're totally stumped by a problem like this one, you can always plug in the answer choices to see which one works!