Question

(1+2i)(2+I)+____=5(2+I)

Answer 1

10

Explanation:

(1 +2i)(2 +i) + __ = 5(2 +i) . . . . given

2 +5i -2 + __ = 10 +5i . . . . . . eliminate parentheses

__ = 10 . . . . . . . . . . . . . . . . . . subtract 5i, simplify

The number that goes in the blank is 10.