Question

How do you subtract `(-9+61)-(3+i)`?

Answer 1

I suspect that your first bracket should be: `(-9+6i)`
In this case you have:
`(-9+6i)-(3+i)=`
`-9+6i-3-i=` you add together (respecting the sign) the real and the immaginary:
`(-9-3)+i(6-1)=-12+5i`