Chapter 4 Quadratic Functions and Factoring - 4.6 Perform Operations with Complex Numbers - Guided Practice for Examples 3, 4, and 5 - Page 278: 13

2.5-2.5i

Multiplying by the conjugate, we find: $$5(1-i)\times (.5)$$ For imaginary numbers, we know that standard form is $a\pm bi$, where $a$ is the real part and $b$ is the imaginary part. We also know that $i^2=-1$. Thus, we simplify the expression until it is in standard form to obtain: $$2.5-2.5i$$