algebra maginary numbers
posted by mada .
just expand it as if the i was a variable
= 9 - 12i + 12i -12i^2, now remember i^2 = -1
= 9 - 12(-1)
wait when you factor it wouldnt it be 9-12i+12i-16i^2
of course, my silly error
its totally cool you have helped alot :)