Question

How do you multiply `(3+2i)(1-3i)`?

Answer 1

Just as any other polynomial, except whenever you get `i^2` you change it to `-1`

Let's go:

`(3+2i)(1-3i)=3*1+3*(-3i)+2i*1-2i*3i`
`=3-9i+2i-6i^2=3-7i+2i^2`

The `i^2` changes into `-1` so the answer is:

`3-7i+2*(-1)=3+7i-2=1+7i`