Answer
$2\sqrt{7}$
Work Step by Step
Getting the perfect factors and then extracting its root, the simplified form of the given expression, $
\sqrt{28}
,$ is
\begin{array}{l}\require{cancel}
\sqrt{4\cdot7}
\\\\=
\sqrt{(2)^2\cdot7}
\\\\=
2\sqrt{7}
.\end{array}
