How do you simplify 3sqrt5+6sqrt5?

2 Answers
Mar 30, 2017

$9 \sqrt{5}$

Explanation:

When adding or subracting, the radicals have to be the same.

$3 \sqrt{5} + 6 \sqrt{5}$

Since $3$ & $6$ have the same radical, we simply add them.

$\left(3 + 6\right) \sqrt{5}$

$9 \sqrt{5}$

$\sqrt{5}$ cannot be written in any simpler form so our answer is

$9 \sqrt{5}$

Mar 30, 2017

$9 \sqrt{5}$

Explanation:

We can add/subtract radicals in the same way we add/subtract like algebraic terms.

$\text{That is } \textcolor{red}{3} x + \textcolor{red}{6} x = \left(\textcolor{red}{3 + 6}\right) x = 9 x$

$\Rightarrow \textcolor{red}{3} \sqrt{5} + \textcolor{red}{6} \sqrt{5} = \left(\textcolor{red}{3 + 6}\right) \sqrt{5} = 9 \sqrt{5}$