SAT Math Multiple Choice Practice Question 430: Answer and Explanation
13. If |x| ≠ 0, which of the following statements must be true?
A. x is positive.
B. 2x is positive.
C. is positive.
D. x2 is positive.
E. x3 is positive.
Correct Answer: D
D There are variables in the answer choices, and the question asks you what must be true. This indicates that you will need to plug in values for x, possibly more than once. Try both –2 and 3. Only D remains true for both. Remember that the square of any nonzero number, either positive or negative, is always positive.