Question

How do you multiply `2i(4-5i)(4+5i)`?

Answer 1

`82i`

Explanation:

`"expand the factors then multiply by "2i`

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

`(4-5i)(4+5i)=16-25i^2=41`

`2ixx41=82i`