Question

How do you simplify `-6i(8-6i)(-8-8i)`?

Answer 1

`-96+672i`

Explanation:

Before multiplying by - 6i , expand the brackets, using for example, the FOIL method.

`rArr(8-6i)(-8-8i)=-64-64i+48i+48i^2`

`color(orange)"Reminder " color(red)(bar(ul(|color(white)(a/a)color(black)(i^2=(sqrt(-1))^2=-1)color(white)(a/a)|)))`

`rArr(8-6i)(-8-8i)=-16i-112`

and `-6i(-16i-112)=96i^2+672i=-96+672i`