Rational expressions and rational equations

Introduction

An expression that is a ratio of two polynomials is called a rational expression.

That is, a rational expression has the form $\dfrac{p(x)}{q(x)}$, where $p(x)$ and $q(x)$ are polynomials.

$\dfrac{2x^2+11}{4x+8}$ is a rational expression.

An equation that contains one or more ratios of polynomials (with polynomials in the numerator and denominator) is called a rational equation.

$\dfrac{x}{2x+5}+5=\dfrac{4x^2+5}{3x-5}$ is a rational equation.

Sections in this chapter

Rational functions

Rational functions, evaluating them, and the domain of a rational function.

Simplifying rational expressions

Simplifying rational expressions by factoring and canceling common factors.

Multiplication and division of rational expressions

Multiplying and dividing rational expressions.

Addition and subtraction of rational expressions

Adding and subtracting rational expressions, including the least common denominator.

Complex fractions

Simplifying complex fractions.

Solving rational equations

Solving rational equations and proportions.