Fractional Equations
7-4Fractional Equations
Overview
Equations where the variable appears in a denominator. Multiply by the LCD, then check for extraneous solutions.
Key ideas
- Multiply by LCD to clear fractions.
- Check for values that make a denominator 0.
- Discard extraneous solutions.
Worked examples
Example 1
Problem. Solve 1/x + 1/2 = 3/4.
Solution. LCD 4x. 4 + 2x = 3x → x = 4. (Check x ≠ 0.) ✓
Practice
Try each one. Click Show answer when ready.
- 1.
Solve 3/x = 6.
- 2.
Solve 1/x + 1/x = 1.
- 3.
Solve 5/x − 2 = 3.
Challenge problems
A little tougher — great for test prep. Click Show answer when ready.
- 1.
Solve: 3/(x+1) = 2/(x−1).
- 2.
Solve: 5/x + 3/(x+2) = 2.