Prove that if w,z are complex numbers such that |w|=|z|=1 and wz\=-1, then w+z/1+wz is a real number

I so far i have determined that w and z both have to equal less than one, but i cannot figure out how to prove this. if wz does not equal one it must mean that w and z both equal less than one. i'm not sure anything i have done is right if someone could look at this it would be amazing, thank you.

1 answer

The mean of four consecutive even numbers is 15.

The greatest of these numbers is a1.

The least of these numbers is