Answer:
Step-by-step explanation:
d) (-2 +4i) -( 3 + 9i) = -2 + 4i - 3 - 9i
= -2 - 3 + 4i - 9i
= -5 - 5i
e)3i(6 - 5i) = 3i *6 - 5i * 3i
= 18i - 15*i² {i² = -1}
= 18i -15*(-1)
= 18i + 15
= 15 + 18i
f) (-3 + 7i)(1 - 2i) = (-3)*1 - 2i * (-3) + 7i *1 - 2i* 7i
= -3 + 6i + 7i - 14i²
= -3 + 6i + 7i - 14*(-1)
= -3 + 6i+ 7i + 14
= 11 + 13i
