Answer:
a) 17.6 + 5.4i
b) 37.6
Step-by-step explanation:
a) (9 + 9.4i) + (8.6 - 4i)
Collect like terms:
9 + 8.6 + 9.4i - 4i
= 17.6 + 5.4i
b) (9.4i)(-4i)
Expand the brackets:
9.4 * -4 * i * i
[tex]i = \sqrt{-1}[/tex]
Therefore, i * i = -1
=> (9.4i)(-4i) = -37.6 * -1
= 37.6