Question

How do I solve this? (Algebra 2:complex numbers)

Answer 1

well what is the conjugate of the complex number z = a + ib? It is a - ib.

now the product of z and its conjugate is

\[(a+ib)(a-ib) = a^2 - i^2b^2 = a^2 +b^2\]

So in other words square the real and imaginary parts and add them