Answer
$|2|x$
Work Step by Step
As per the product rule, we have $\sqrt[n] {pq}=\sqrt[n] {p}\sqrt[n] {q}$
Given: $\sqrt[4] {16x^4}$
Which can be written as: $\sqrt[4] {16x^4}=\sqrt[4] {16}\sqrt[4] {x^4}$
or, $=\sqrt[4] {2^4}\sqrt[4] {x^4}$
or, $=|2|x$
