How do you combine sqrt80+sqrt45-sqrt20?

Apr 29, 2018

$5 \sqrt{5}$

Explanation:

$\sqrt{80} + \sqrt{45} - \sqrt{20}$

Simplify:
$\sqrt{16 \cdot 5} + \sqrt{9 \cdot 5} - \sqrt{4 \cdot 5}$

$\sqrt{16} \cdot \sqrt{5} + \sqrt{9} \cdot \sqrt{5} - \sqrt{4} \cdot \sqrt{5}$

$4 \cdot \sqrt{5} + 3 \cdot \sqrt{5} - 2 \cdot \sqrt{5}$

$4 \sqrt{5} + 3 \sqrt{5} - 2 \sqrt{5}$

Since the value inside each of the square root signs are the same, that means we can do: $4 + 3 - 2$, which equals $5$

$5 \sqrt{5}$