Answer
$4(x^3+4)(x^3-4)$
Work Step by Step
Factoring the $GCF=
4
$, then the given expression, $
4x^6-64
$ is equivalent to
\begin{array}{l}
4(x^6-16)
.\end{array}
Using $a^2-b^2=(a+b)(a-b)$ or the factoring of the difference of $2$ squares, then the complete factored form of the expression above is
\begin{array}{l}
4(x^3+4)(x^3-4)
.\end{array}