I need to solve the following equation and i am encountering some problem

Re: (z+i)/(1-z)=0

This is what i did so far:

Re:

(z+i)/(1-z) +1 = 1

(1+i)/(z-1)=-1

.

and then i multiply left side with (z(conjugate)-1)/(z(conjugate)-1).

After all the calculations i get the following equation and i don't know which a or b value is correct:

a(a+1)+b(b+1)=0

z=complex number, a= Re value of complex number, b=Im value of complex number

I hope i've expressed myself clear and thank you for your help.