Answer
$5x^2y^4\sqrt {2}$
Work Step by Step
Rewrite the radicand as a product of at least one square so that we can take something out from the radical sign. The number $50$ can be rewritten as $(25)(2)$:
$\sqrt {(25)(2)(x^4)(y^8)}$
Rewrite $25$ as $5^2$, $x^4$ as $(x^2)^2$, and $y*8$ as $(y^4)^2$:
$=\sqrt {(5^2)(2)(x^2)^2(y^4)^2}$
Take out the square roots of everything that is raised to the power of $2$ from under the radical sign:
$=5x^2y^4\sqrt {2}$
