How do you simplify $\sqrt{3} (- 3 \sqrt{7})$ $sqrt3(-3sqrt7)$ ?

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Answer 1 · 2016-06-17T16:16:18

$- 3 \sqrt{21}$ $-3sqrt21$

Multiply the bracket out to give $- 3 \times \sqrt{3} \times \sqrt{7}$ $-3 xx sqrt3 xx sqrt7$

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

$- 3 \sqrt{21}$ $-3sqrt21$

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.

How do you simplify √3(−3√7)sqrt3(-3sqrt7)?