Question

How do you multiply `(-3-7i)(-12-2i)`?

Answer 1

`22+90i`

Explanation:

`"note "i^2=(sqrt(-1))^2=-1`

`"expand using FOIL and collect like terms"`

`rArr(-3-7i)(-12-2i)`

`=36+6i+84i+14i^2`

`=36+90i-14`

`=22+90ilarrcolor(red)"in standard form"`