Algebra 2 Lesson #48 Introduction to Rational Expressions | Simplifying | Find the Domain

In this lesson, we will introduce the concept of a rational expression. A rational expression is the quotient of two polynomials, with a non-zero denominator. The first task is to learn how to find the domain of the rational expression. This is the set of allowable values for x. The idea is we can't divide by zero. We will set the denominator equal to zero and solve the resulting equation. The solution(s) will be restricted from the domain since they make the denominator zero. Secondly, we will learn how to simplify a rational expression. This is done by factoring both numerator and denominator completely and then canceling any common factors.