#### Answer

$\color{blue}{5xy^3\sqrt{2}}$

#### Work Step by Step

Factor the radicand so that at least one factor is a perfect square:
$=\sqrt{(25x^2y^6)(2)}
\\=\sqrt{(5xy^3)^2(2)}$
Bring out the square root of the perfect square factor to obtain:
$=\color{blue}{5xy^3\sqrt{2}}$