Question

How do you simplify `5/(1+2i)`?

Answer 1

I found: `1-2i`

Explanation:

I would multiply and divide by the complex conjugate of the denominator, i.e., `1-2i` to get:
`5/(1+2i)*(1-2i)/(1-2i)=(5-10i)/(1cancel(-2i)cancel(+2i)-4i^2)=`
remembering that `i^2=-1`
`=(5-10i)/(1+4)=(5-10i)/5=5/5-10/5i=1-2i`