Evaluate this complex number multiplication
(9 - 6i)(2 - 4i)
(a * c) + (b * c) + (a * d) + (b * d)
a = 9, b = -6, c = 2, and d = -4
(9 - 6i)(2 - 4i) = (9 * 2) + (-6i * 2) + (9 * -4i) + (-6i * -4i)
(9 - 6i)(2 - 4i) = 18 - 12i - 36i + 24i2
(9 - 6i)(2 - 4i) = 18 + (-12 - 36)i + 24i2
(9 - 6i)(2 - 4i) = 18 - 48i + 24i2
i2 = √-1 * √-1 = -1, so our last term becomes:
(9 - 6i)(2 - 4i) = 18 - 48i + 24* (-1)
(9 - 6i)(2 - 4i) = 18 - 48i - 24
(9 - 6i)(2 - 4i) = (18 - 24) - 48i
(9 - 6i)(2 - 4i) = -6 - 48i