Question

How do you simplify `(3 + 2i)(2 − i)` and write in a+bi form?

Answer 1

`8+i`

Explanation:

You can simply multiply the two parenthesis as you do with normal number, and then remember that you can sum immaginary numbers (e.g. `3i+5i=8i`) and that `i^2=-1`. So, you have

`(3+2i)(2-i) =`

`6-3i+4i-2i^2=`

`6+i-2(-1)=`

`6+i+2 = 8+i`