Question

Simplify the expression (3 + 7i)(3 − 7i).
A. 40
B. 58
C. 9 − 21i
D. 9 + 21i

Answer 1

Answer:

B. 58 is your answer.

Step-by-step explanation:

(3 + 7i)(3 - 7i)

9 + 21i -21i -49i^2

The 21i and -21i cancel out.

9-49i^2 The i^2 becomes -1

9-49(-1)

9+49

B. 58 is your answer.