# How do you simplify -3sqrt5*sqrt20?

Mar 28, 2018

$- 30$

#### Explanation:

$- 3 \sqrt{5} \cdot \sqrt{4 \cdot 5}$
$- 3 \sqrt{5} \cdot 2 \sqrt{5}$
$- 6 \cdot 5$
$- 30$

Mar 28, 2018

Combine terms in the radical to find the simplified expression is -30

#### Explanation:

We can multiply the radicals directly, since they're the same root:

$- 3 \sqrt{5} \cdot \sqrt{20} = - 3 \sqrt{5 \cdot 20}$

Once we carry out the multiplication under the radical, we can then simplify:

$\Rightarrow - 3 \sqrt{100} = - 3 \cdot 10$

$\textcolor{red}{\Rightarrow - 30}$