Answer
$$4x^2$$
Work Step by Step
RECALL:
(1) If $n$ is odd, then $\sqrt[n]{a^n}=a$.
(2) If $n$ is even, then $\sqrt[n]{a^n} = |a|$
Use rule (1) above to obtain:
\begin{align*}
\sqrt[3]{64x^6}&=\sqrt[3]{(4)(4)(4)(x^2)(x^2)(x^2)}\\
&=\sqrt[3]{(4x^2)^3}\\
&=4x^2
\end{align*}
