How to Solve Rational Equations? (+FREE Worksheet!)
An equation that consists of at least one Rational expression is a Rational equation, and in this article, we will teach you how to solve this type of equation using two methods.
Related Topics
- How to Add and Subtract Rational Expressions
- How to Multiply Rational Expressions
- How to Divide Rational Expressions
- How to Simplify Complex Fractions
- How to Graph Rational Expressions
A step-by-step guide to solve Rational Equations
For solving rational equations, we can use following methods:
- Converting to a common denominator: In this method, you need to get a common denominator for both sides of the equation. Then, make numerators equal and solve for the variable.
- Cross-multiplying: This method is useful when there is only one fraction on each side of the equation. Simply multiply the first numerator by the second denominator and make the result equal to the product of the second numerator and the first denominator.
Examples
Rational Equations – Example 1:
Solve. \(\frac{x – 2}{x + 1 }=\frac{x + 4}{x – 2}\)
Solution:
Use cross multiply method: if \(\frac{a}{b}=\frac{c}{d}\), then: \(a×d=b×c \)
\(\frac{x – 2}{x + 1 }=\frac{x + 4}{x – 2}→(x-2)(x-2)=(x+4)(x+1)\)
Expand: \((x-2)^2=x^2-4x+4\) and \((x+4)(x+1)=x^2+5x+4\), Then:
\( x^2-4x+4=x^2+5x+4\), Now, simplify: \(x^2-4x=x^2+5x\), subtract both sides \((x^2+5x)\), Then: \(x^2-4x-(x^2+5x)=x^2+5x-(x^2+5x)→ -9x=0→x=0\)
Rational Equations – Example 2:
Solve. \(\frac{x – 3}{x + 1 }=\frac{x + 5}{x – 2}\)
Solution:
Use cross multiply method: if \(\frac{a}{b}=\frac{c}{d}\), then: \(a×d=b×c\)
Then: \((x-3)(x-2)=(x+5)(x+1)\)
Expand: \((x – 3)(x-2)=x^2-5x+6\)
Expand: \((x+5)(x+1)=x^2+6x+5\), Then: \(x^2-5x+6=x^2+6x+5\), Simplify: \(x^2-5x=x^2+6x-1\)
Subtract both sides \(x^2+6x ,Then: -11x=-1→x=\frac{1}{11}\)
Rational Equations – Example 3:
Solve. \(\frac{x +3}{x + 6 }=\frac{x + 2}{x – 4}\)
Solution:
Use cross multiply method: if \(\frac{a}{b}=\frac{c}{d}\), then: \(a×d=b×c \)
\(\frac{x+3}{x +6 }=\frac{x + 2}{x – 4}→(x+3)(x-4)=(x+2)(x+6)\)
Expand: \((x + 3)(x-4)=x^2-x-12\)
Expand: \((x+2)(x+6)=x^2+8x+12\), Then: \(x^2-x-12=x^2+8x+12\), Simplify: \(x^2-x=x^2+8x+24\)
Subtract both sides \(x^2+8x ,Then: -9x=24→x=-\frac{24}{9}=-\frac{8}{3}\)
Rational Equations – Example 4:
Solve. \(\frac{x +5}{x + 2 }=\frac{x -5}{x +3}\)
Solution:
Use cross multiply method: if \(\frac{a}{b}=\frac{c}{d}\), then: \(a×d=b×c \)
\(\frac{x+5}{x +2 }=\frac{x -5}{x+3}→(x+5)(x+3)=(x-5)(x+2)\)
Expand: \((x + 5)(x+3)=x^2+8x+15\)
Expand: \((x-5)(x+2)=x^2-3x-10\), Then: \(x^2+8x+15=x^2-3x-10\), Simplify: \(x^2+8x=x^2-3x-25\)
Subtract both sides \(x^2-3x ,Then: 11x=-25→x=-\frac{25}{11}\)
Exercises for Rational Equations
Solve Rational Equations.
- \(\color{blue}{\frac{10}{x+4}=\frac{15}{4x+4}}\)
- \(\color{blue}{\frac{x+4}{x+1}=\frac{x-6}{x-1}}\)
- \(\color{blue}{\frac{2x}{x+3}=\frac{x-6}{x+4}}\)
- \(\color{blue}{\frac{1}{x+5}-1=\frac{1}{1+x}}\)
- \(\color{blue}{\frac{1}{5x^2}-\frac{1}{x}=\frac{2}{x}}\)
- \(\color{blue}{\frac{2x}{2x-2}-\frac{2}{x}=\frac{1}{x-1}}\)
- \(\color{blue}{x=\frac{4}{5}}\)
- \(\color{blue}{x=-\frac{1}{4}}\)
- \(\color{blue}{x=-9}\) or \(\color{blue}{x=-2}\)
- \(\color{blue}{x=-3}\)
- \(\color{blue}{x=\frac{1}{15}}\)
- \(\color{blue}{x=2}\)
The Absolute Best Book for the Algebra Test
Related to This Article
More math articles
- How to Solve Multiplication Inequalities
- The Ultimate 6th Grade Scantron Performance Math Course (+FREE Worksheets)
- Completing the Puzzle: How to Finishing Equations when Multiplying Fractions by Whole Numbers Using Models
- 8th Grade Common Core Math Worksheets: FREE & Printable
- Top 10 Geometry Books for High School Students
- How to Use Order of Operations? (+FREE Worksheet!)
- 7th Grade Common Core Math Practice Test Questions
- FREE 7th Grade OST Math Practice Test
- The Ultimate 7th Grade NJSLA Math Course (+FREE Worksheets)
- How to Graph the Cotangent Function?
What people say about "How to Solve Rational Equations? (+FREE Worksheet!) - Effortless Math: We Help Students Learn to LOVE Mathematics"?
No one replied yet.