AlgebraLab

Algebra I Recipe: Solving Absolute Value Inequalities

By G Redden

Steps
  1. Isolate the absolute value using inverse operations.
  2. Write a compound sentence.
    • With “AND” if you have <  or  ≤ after isolating.
    • With “OR” if you have >  or  ≥ after isolating
    • Sentence 1 – is the isolated inequality without the absolute value bars
    • Sentence 2 – looks like sentence 1 except change the inequality symbol and change the number on the right to it’s opposite.
  3. Solve each sentence (inequality) for the variable.
  4. Graph the solution.
1.
| 3x - 15| < 12
2.
| 4 - x | ≥  2
3.
| 5x + 1 | - 8  ≤  16
4.
| 2x + 5 | - 1 < 6
5.
| 3x + 2 | - 1  ≥  10