How do you solve a complex equation

Question

 x^2+4x=-20

Answer 1

x^2 + 4x + 20 =0

Using quadratic formula,

x = (-b ± √(b^2 - 4 a c)) / (2a) where a = 1, b = 4 and c = 20.

x = (-4 ± √(4^2 - 4 * 1 * 20)) / (2 * 1)

x =(-4 ± √-64) / 2

x = (-4 ± 8i) / 2

x = 2(-2 ± 4i) / 2

x = -2 + 4i or -2 - 4i