Question

help : multiply out (9-6i)^2

Answer 1

(9 - 6i)(9 - 6i) you foil
81 - 54i - 54i - 36 (-6i)(-6i) is -36 because - times a - is a positive but i^2 = -1

add like terms

Answer 2

81 - 36 = 45
-54i - 54i = -108i

so you get 45 - 108i

Answer 3

y (-6i)(-6i)=-36 , it's not 36i^2?

Answer 4

i^2 = -1 by definition

so 36(-1) = -36

Answer 5

thank u.