Chapter 2 - Real Numbers - 2.3 - Real Numbers and Algebraic Expressions - Problem Set 2.3 - Page 69: 96

The answer is below.

There are many answers to this question. However, for the purposes of Algebra students, real numbers have essentially been the basis for all Math that you have been doing. In this sense, this question is very broad as the properties of real numbers have been a basis for nearly everything that you have done.