Answer
$3x^2y^4\sqrt{2x}$
Work Step by Step
Getting the factors that are perfect roots of the index, the given expression, $
\sqrt{18x^5y^8}
,$ simplifies to
\begin{array}{l}\require{cancel}
\sqrt{9x^4y^8\cdot2x}
\\\\=
\sqrt{(3x^2y^4)^2\cdot2x}
\\\\=
3x^2y^4\sqrt{2x}
.\end{array}
Note that the variables are assumed to contain positive real numbers.
