Question

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

Answer 1

`-4i(3-5i)=-20-12i`

Explanation:

`-4i(3-5i)=(-4i)xx3-(-4i)xx(5i)=-12i+20i^2`

It is assumed that `i` is not a variable, but is a unit imaginary number and hence `i^2=-1` and hence

`-4i(3-5i)=-12i+20i^2=-12i-20` or `-20-12i`