# How do you simplify 5sqrt(2y^2)-3ysqrt8?

Apr 12, 2017

$= - y \sqrt{2}$

#### Explanation:

Extract any roots that you can.

$5 \sqrt{2 \textcolor{red}{{y}^{2}}} - 3 y \sqrt{\textcolor{b l u e}{4} \times 2} \text{ } \leftarrow \left(8 = 4 \times 2\right)$

$= 5 \textcolor{red}{y} \sqrt{2} - 3 \times \textcolor{b l u e}{2} y \sqrt{2}$

$= 5 y \sqrt{2} - 6 y \sqrt{2} \text{ } \leftarrow$ these are like terms

$= - y \sqrt{2}$