I know you use the conjugate but I'm pretty confused after that
\(For z = -3 + 5i, evaluate z \overline{z}.\)
If \(z = a + bi\), then \(\overline{z} = a - bi\). So, \(z \overline{z} = (a + bi)(a-bi) = a^2 + b^2\). Since \((a, b) = (3, 5)\), we have \(z \overline{z} = 3^{2} + 5^{2} = 41.\)