What is the volume of a cube with 1/2 inch sides?

Pls! does anybody know a shortcut for answering these types of questions in the future?

[10 points, algebra 2-simplifying complex fractions]according to my answer key the restrictions are -1 and 4. but why not positive 1?

Simplify (2^5/3^2)^4 a. 2^20/3^8 b. 2^9/3^8 c. 8^5/12^2 d. 2/3^2