# Chapter 11 - Additional Topics - 11.4 - Complex Numbers - Problem Set 11.4: 55

#### Work Step by Step

Complex numbers are "complex" because they contain multiple types of numbers--real numbers and imaginary numbers. After all, when we add 1 and $2i$, we are adding a real and an imaginary number. Thus, real numbers are a subset of imaginary numbers as they are included in the set of imaginary numbers.

After you claim an answer you’ll have 24 hours to send in a draft. An editor will review the submission and either publish your submission or provide feedback.