Question

Multiply the following complex numbers:

(8 - 3i)(6 + 5i)
A. 33 + 221
B. 33 - 221
C. 63 + 221
O D. 63 - 221

Answer 1

63+22i

Explanation:

(8 - 3i)(6 + 5i)

FOIL

first: 8*6 = 48

outer: 8*5i = 40i

inner: -3i* 6 = -18i

last: -3i*5i = -15 i^2 = -15(-1) = 15

Add together

48+40i -18i +15

Combine like terms

63+22i