The system of equations

has two solutions and in complex numbers. Find .

So far I replaced z with a+bi, did some algebra (squared both equations) and ended up with these equations:

a^2 + b^2 + (4-4a)i + 4b = 23

and

a^2 + b^2 - 16a + 10b + (80 - 10a - 16b )i = -1

Not sure where to go from here. Thanks!