Answer
6$x^{2}$
Work Step by Step
You have (36$x^{4}$$)^{1/2}$. Since anything raised to a half is basically like finding its square root, you will have:
($\sqrt 36$) ($\sqrt x^4$)
The square root of 36 is 6 and the square root of $x^{4}$ is $x^{2}$.So the simplified expression is:6$x^{2}$