Chapter 21.5
Solving rational equations
What You'll Learn
Identify non-permissible values by setting denominators not equal to zero
Solve rational equations by eliminating denominators through multiplication
Apply cross-multiplication when equations have single fractions on each side
Simplify rational equations by factoring and canceling common terms
Verify solutions against non-permissible values to reject invalid answers
What You'll Practice
1
Finding non-permissible values from rational expressions with variable denominators
2
Solving equations by multiplying through by the LCD to clear fractions
3
Cross-multiplying rational equations and solving resulting linear or quadratic equations
4
Factoring quadratic numerators and canceling common factors before solving
Why This Matters
Solving rational equations is essential for algebra, calculus, and real-world applications like rate problems and proportional relationships. Mastering this skill helps you handle complex fractions in physics formulas, chemistry calculations, and engineering problems where variables appear in denominators.
Before You Start — Make Sure You Can:
This Unit Includes
9 Video lessons
Practice exercises
Skills
Rational Equations
Non-Permissible Values
Cross-Multiplication
LCD
Factoring
Quadratic Equations
Algebra
