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

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Answer 1 · 2018-04-08T15:48:19

$color(blue)(-12)$

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

$ixxi=-1$

Expanding:

$sqrt(2) * (-3sqrt(2))+sqrt(2) * (-3sqrt(2)i)-sqrt(2)i*(-3sqrt(2 ))-sqrt(2)i*(-3sqrt(2)i)$

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

$color(blue)(-12)$

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