# How do you simplify (7sqrt5)^2?

$245$
${\left(a \cdot b\right)}^{2}$ can be expanded as $\left({a}^{2} \cdot {b}^{2}\right)$
So, ${\left(7 \cdot \sqrt{5}\right)}^{2}$ can be written as ${7}^{2} \cdot {\left(\sqrt{5}\right)}^{2}$ => $49 \cdot 5$ => $245$