Question

(4x)^-2

Answer 1

A negative exponent means the stuff in the parentheses dividing 1, for example...
\[\frac{ 1 }{ x }=x^{-1}\]
Therefore \[4x^{-2}=\frac{ 1 }{ (4x)^{2}}\]

Answer 2

If a quantity in a parenthesis is raised to a power, we must raise EVERYTHING inside that quantity to the power.

For example:
\[(3g)^{3}=9g^{3} \]

Can you go from there?