# How do you simplify: 4 times the square root of 18?

Jul 26, 2015

$4 \sqrt{18} = 12 \sqrt{2}$

#### Explanation:

$4 \sqrt{18}$

Factor $18$ into its prime factors.y

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

$4 \sqrt{\left(3 \times 3\right) \times 2}$

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

Apply the rule $\sqrt{{a}^{2}} = a$

$4 \times 3 \sqrt{2}$

$12 \sqrt{2}$