Answer
$a)$ $\sqrt[4]{x^{4}y^{2}z^{2}}=x\sqrt{yz}$
$b)$ $\sqrt[3]{\sqrt{64x^{6}}}=2x$
Work Step by Step
$a)$ $\sqrt[4]{x^{4}y^{2}z^{2}}$
Take the 4th root of each factor.
$\sqrt[4]{x^{4}y^{2}z^{2}}=(\sqrt[4]{x^{4}})(\sqrt[4]{y^{2}z^{2}})=x\sqrt{yz}$
$b)$ $\sqrt[3]{\sqrt{64x^{6}}}$
Evaluate $\sqrt{64x^{6}}$
$\sqrt[3]{\sqrt{64x^{6}}}=\sqrt[3]{8x^{3}}=...$
Take the cubic root of each factor:
$...=(\sqrt[3]{8})(\sqrt[3]{x^{3}})=2x$
