Learn on PengiOpenstax Intermediate Algebra 2EChapter 7: Rational Expressions and Functions

Lesson 7.3: Simplify Complex Rational Expressions

In this lesson from OpenStax Intermediate Algebra 2E, students learn to simplify complex rational expressions — rational expressions that contain other rational expressions in their numerator or denominator. The lesson covers two methods: rewriting the complex expression as division and multiplying by the reciprocal, and using the least common denominator (LCD) to combine and reduce terms. Students practice applying factoring, finding LCDs, and identifying excluded values throughout the simplification process.

Section 1

📘 Simplify Complex Rational Expressions

New Concept

A complex rational expression is a fraction that contains other fractions in its numerator or denominator. This lesson teaches two powerful methods to simplify them: rewriting as division or clearing fractions using the Least Common Denominator (LCD).

What’s next

Next, you’ll apply these two methods. We'll start with interactive examples and then move on to practice cards to master each technique.

Section 2

Complex Rational Expression

Property

A complex rational expression is a rational expression in which the numerator and/or the denominator contains a rational expression.

Examples

  • The expression x2x28\dfrac{\dfrac{x}{2}}{\dfrac{x^2}{8}} is a complex rational expression.
  • The expression 1a+35a2\dfrac{\dfrac{1}{a} + 3}{\dfrac{5}{a^2}} contains addition in the numerator.

Section 3

Simplify by Writing as Division

Property

To simplify a complex rational expression by writing it as division:

Step 1. Simplify the numerator and denominator so that each is a single rational expression.

Step 2. Rewrite the complex rational expression as a division problem.

Section 4

Simplify Using the LCD

Property

To simplify a complex rational expression by using the LCD:

Step 1. Find the LCD of all fractions in the complex rational expression.

Step 2. Multiply the numerator and denominator by the LCD.

Book overview

Jump across lessons in the current chapter without opening the full course modal.

Continue this chapter

Chapter 7: Rational Expressions and Functions

  1. Lesson 1

    Lesson 7.1: Multiply and Divide Rational Expressions

  2. Lesson 2

    Lesson 7.2: Add and Subtract Rational Expressions

  3. Lesson 3Current

    Lesson 7.3: Simplify Complex Rational Expressions

  4. Lesson 4

    Lesson 7.4: Solve Rational Equations

  5. Lesson 5

    Lesson 7.5: Solve Applications with Rational Equations

  6. Lesson 6

    Lesson 7.6: Solve Rational Inequalities

Lesson overview

Expand to review the lesson summary and core properties.

Expand

Section 1

📘 Simplify Complex Rational Expressions

New Concept

A complex rational expression is a fraction that contains other fractions in its numerator or denominator. This lesson teaches two powerful methods to simplify them: rewriting as division or clearing fractions using the Least Common Denominator (LCD).

What’s next

Next, you’ll apply these two methods. We'll start with interactive examples and then move on to practice cards to master each technique.

Section 2

Complex Rational Expression

Property

A complex rational expression is a rational expression in which the numerator and/or the denominator contains a rational expression.

Examples

  • The expression x2x28\dfrac{\dfrac{x}{2}}{\dfrac{x^2}{8}} is a complex rational expression.
  • The expression 1a+35a2\dfrac{\dfrac{1}{a} + 3}{\dfrac{5}{a^2}} contains addition in the numerator.

Section 3

Simplify by Writing as Division

Property

To simplify a complex rational expression by writing it as division:

Step 1. Simplify the numerator and denominator so that each is a single rational expression.

Step 2. Rewrite the complex rational expression as a division problem.

Section 4

Simplify Using the LCD

Property

To simplify a complex rational expression by using the LCD:

Step 1. Find the LCD of all fractions in the complex rational expression.

Step 2. Multiply the numerator and denominator by the LCD.

Book overview

Jump across lessons in the current chapter without opening the full course modal.

Continue this chapter

Chapter 7: Rational Expressions and Functions

  1. Lesson 1

    Lesson 7.1: Multiply and Divide Rational Expressions

  2. Lesson 2

    Lesson 7.2: Add and Subtract Rational Expressions

  3. Lesson 3Current

    Lesson 7.3: Simplify Complex Rational Expressions

  4. Lesson 4

    Lesson 7.4: Solve Rational Equations

  5. Lesson 5

    Lesson 7.5: Solve Applications with Rational Equations

  6. Lesson 6

    Lesson 7.6: Solve Rational Inequalities