Use the distributive property to multiply everything in parantheses:
(11 - 12i)(-4 + 6i) = 0
-44 + 66i + 48i + -72i = 0
Factor out the greatest common factor, 2:
2(-22 + 57i + -36i^2) = 0
Factor a trinomial:
2((-11 + 12i)(2 + -3i)) = 0
Set each subproblem equal to 0:
-11 + 12i = 0 2 + -3i = 0
-11 + 12i + 11 = 0 + 11 2 + -3i - 2 = 0 - 2
12i = 11 -3i = -2
i = 0.917 i = 0.667
