Answer
$5i\sqrt{2}$
Work Step by Step
Using the Product Rule of radicals which is given by $\sqrt[m]{x}\cdot\sqrt[m]{y}=\sqrt[m]{xy},$ the given expression is equivalent to\begin{array}{l}\require{cancel}
\sqrt{-50}
\\\\=
\sqrt{-1}\cdot\sqrt{50}
.\end{array}
Using $i=\sqrt{-1}$ and extracting the factors that are perfect powers of the index, the expression above simplifies to
\begin{array}{l}\require{cancel}
\sqrt{-1}\cdot\sqrt{50}
\\\\=
i\sqrt{25\cdot2}
\\\\=
i\sqrt{(5)^2\cdot2}
\\\\=
5i\sqrt{2}
.\end{array}
