View more at http://www.MathTutorDVD.com. In this lesson, you will learn what a square root is and why they are important in algebra. We will learn to simplify algebraic expressions that involve square roots by using the concept of a factor tree. A factor tree is the process of determining all factors or a number or algebraic expressions. Once we write the factor tree, we can find the square root of the expression by looking for pairs of numbers in the "bottom" factors of the tree.