factor down (4^3)^2

Question

____ * _____
______ _______ ______*______ _____ ____

when is it not possible to work an exponent multipication?
In the space below give an example and work it out to prove what you say does not work

Answer 1

(4^3)^2 = 4^6 = 4^3 * 4^3 = 4 * 4 * 4 * 4 * 4 * 4 = 4,096

I don't know when it is not possible.