Question

How do you multiply `(3+5i)(4+4i)`?

Answer 1

I found: `-8+32i`

Explanation:

You go as for a normal distributive BUT remembering that `i^2=-1`.
So:
`(3+5i)(4+4i)=(3*4)+(3*4i)+(5i*4)+(5i*4i)=`
`=12+12i+20i+20i^2=`
add similar terms and remember the significance of `i^2`:
`=12+32i-20=-8+32i`