Question

(15−4i)(6−3i)=a+bi

In the equation above, a and b are real numbers and i=−1‾‾‾√. What is the value of a?

a=

Answer 1

The answer is
a = 15 + 6
= 21

Answer 2

14

Explanation:

15 -4=11

6-3=3

then a minus ND minus it makes a plus the 11+3=14