Chapter 4 - Quadratic Functions and Equations - 4-9 Quadratic Systems - Practice and Problem-Solving Exercises - Page 264: 66

$-4 + 3i$

First, we want to get rid of the parentheses by using the distributive property, but we need to pay attention to the signs: $1 - i - 5 + 4i$ Group like terms: $(1 - 5) + (-i + 4i)$ Combine like terms: $(-4) + (3i)$ Use distributive property to simplify: $-4 + 3i$