Question

Which of the following statements is always true for all values of a

A) -a = a
B) |a| = -a
C) |a| = a
D) -(-a) = a

Answer 1

D because -(-a) is just a. Whenever there are two minus symbols next to each other just change them into plus signs.

Answer 2

D) -(-a) = a because -(-a) is the same thing as positive a