# How do you simplify (sqrt2-sqrt2i)*(-3sqrt2-3sqrt2i)?

Apr 8, 2018

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#### Explanation:

When expanding with complex numbers, we just have to remember that:

$i \times i = - 1$

Expanding:

$\sqrt{2} \cdot \left(- 3 \sqrt{2}\right) + \sqrt{2} \cdot \left(- 3 \sqrt{2} i\right) - \sqrt{2} i \cdot \left(- 3 \sqrt{2}\right) - \sqrt{2} i \cdot \left(- 3 \sqrt{2} i\right)$

$- 6 - 6 i + 6 i - 6$

$\textcolor{b l u e}{- 12}$