Antwoord:
# -28-3i #
Uitleg:
#color (orange) "herinnering" kleur (wit) (x) i ^ 2 = (sqrt (-1)) ^ 2 = -1 #
# "vergroot de factoren op de teller" #
#rArr (15-28i + 12i ^ 2) / i #
# = (3-28i) / i #
# "vermenigvuldig teller / noemer door" i #
# = (I (3-28i)) / i ^ 2 #
# = (28 + 3i) / (- 1) = - 28-3i #
