Question 404784
There are three main rules you must remember when working with exponents:

1. (m^n)^t = m^nt
2. (mt)^n = m^n t^n
3. m^n x m^n = m^n+n

This being said, you just have to find which one of these rules fits for your problem. 

(4x^3)^2

This fits rule number one. 

(4x^3)^2 = 4x^3x2

4x^6