Answer: 9 - 3i
==============================================
Work Shown:
(4+3i) + (5-6i)
4+3i + 5-6i
(4+5) + (3i-6i)
9 + (3-6)i
9 + (-3)i
9 - 3i
As the steps above show, we treat the 'i' as a variable. So we could think of the expression as (4+3x)+(5-6x) and simplify to get 9-3x. Though we use ''i' instead of x.