# How do you simplify -4sqrt72?

Oct 27, 2015

$- 4 \sqrt{72} = - 24 \sqrt{2}$

#### Explanation:

$- 4 \sqrt{72}$

Simplify.;

$- 4 \sqrt{8} \sqrt{9}$

Write the prime factors for $8$ and $9$.

$- 4 \sqrt{2 \times 2 \times 2} \sqrt{3 \times 3}$

Simplify.

$- 4 \sqrt{{2}^{2} \times 2} \sqrt{{3}^{2}}$

Apply square root rule $\sqrt{{4}^{2}} = 4$.

$- 4 \times 2 \times 3 \sqrt{2} =$

$- 24 \sqrt{2}$