Question

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

Answer 1

`color(blue)(-12)`

Explanation:

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)`