How to simplify complex numbers by adding and subtracting

The video tutorial explains how to simplify complex numbers by introducing the imaginary unit 'i' to handle negative square roots. It covers the process of simplifying radicals by identifying the greatest square number and demonstrates combining complex expressions. The tutorial also includes operations with square numbers in complex expressions, providing a step-by-step approach to simplifying and combining these numbers.

What steps are involved in taking the square root of a negative number and how does it relate to complex numbers?

Describe how to multiply complex numbers and provide an example from the text.