Question

How do you multiply `(-4i)(-8-8i)(1-8i)`?

Answer 1

`224i-288`

Explanation:

Distribute `(8-8i)(1-8i)` using the FOIL method, say. Then multiply the result by `(-4i)`

`color(orange)"Reminder: " i^2=(sqrt(-1))^2=-1`

`rArr(8-8i)(1-8i)`

`=8-64i-8i+64i^2`

`=-72i-56`

`rArr(-4i)(-72i-56)`

`=288i^2+224i`

`=224i-288`