Simplify the Radical Expression 9 square root of 8y

$9 \sqrt{8 y}$

Rewrite $8 y$ as $2^{2} \cdot (2 y)$ .

Factor $4$ out of $8$ .

$9 \sqrt{4 (2) y}$

Rewrite $4$ as $2^{2}$ .

$9 \sqrt{2^{2} \cdot 2 y}$

Add parentheses.

$9 \sqrt{2^{2} \cdot (2 y)}$

Pull terms out from under the radical.

$9 (| 2 | \sqrt{2 y})$

The absolute value is the distance between a number and zero. The distance between $0$ and $2$ is $2$ .

$9 (2 \sqrt{2 y})$

Multiply $2$ by $9$ .

$18 \sqrt{2 y}$