# How do you simplify sqrt3(-3sqrt7)?

Jun 17, 2016

$- 3 \sqrt{21}$

#### Explanation:

Multiply the bracket out to give $- 3 \times \sqrt{3} \times \sqrt{7}$

If roots are being multiplied, they can be combined into one.

$- 3 \sqrt{21}$

But I would not say that this is any simpler. 21 has no factors which are squares, so this is as far as we could go without using a calculator.