#### Answer

$x\sqrt{y}$

#### Work Step by Step

Using the properties of radicals, the given expression, $
\sqrt{xy}\sqrt{x}
,$ simplifies to
\begin{array}{l}\require{cancel}
\sqrt{xy(x)}
\\\\=
\sqrt{x^2y}
\\\\=
\sqrt{(x)^2\cdot y}
\\\\=
x\sqrt{y}
.\end{array}
Note that all variables represent positive real numbers.