Maths Library

Solving linear inequalities: Grade 9 math

This topic covers solving linear inequalities and representing their solution sets symbolically and on number lines. The worksheet practises applying inverse operations while carefully managing inequality sign reversals.

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What this covers

Solving linear inequalities is taught in Grade 9 (age 14 to 15) as a topic to introduce. It sits in the Algebra strand.

Worked example

Solve: 5 - 2x <= 13

  1. Subtract 5 from both sides: -2x <= 8
  2. Divide both sides by -2 and reverse the inequality sign: x >= 8 ÷ -2
  3. Simplify the result: x >= -4

Answer: x >= -4

Difficulty scale

The sheet generator offers five difficulty settings for this topic.

  1. One-step inequalities with positive integers, e.g., x + 3 > 7
  2. Two-step inequalities with positive coefficients, e.g., 2x - 5 <= 9
  3. Two-step inequalities requiring division by a negative, flipping the sign
  4. Inequalities with the variable on both sides, e.g., 4x + 1 > x + 10
  5. Double-ended inequalities, e.g., -3 <= 2x + 1 < 9, finding integer solutions

Common mistakes

  • Forgetting to reverse the inequality sign when multiplying or dividing by a negative number
  • Confusing strict inequalities (<, >) with inclusive ones (<=, >=) when plotting on a number line

Curriculum links

Indicative matches to Common Core State Standards. Check wording and codes against the official document.

  • Create equations and inequalities in one variable to model relationships and solve contextual problems.
  • Solve linear equations and inequalities in one variable, including those with coefficients represented by letters.

Sample sheet and answers

Six questions at the level's usual difficulty. Open the editor to change, add or regenerate any of them.

Solving linear inequalities

Grade 9 math

Qs
6
Marks
12
NameDateScore / 12
1.
Solve 2x + 4 ≥ 14
[2]
2.
Solve 4x + 4 ≤ 16
[2]
3.
Solve 3x + 5 ≥ 14
[2]
4.
Solve 2x + 2 ≤ 12
[2]
5.
Solve 4x + 4 ≥ 32
[2]
6.
Solve 2x + 5 ≥ 15
[2]

Answer key

  1. x ≥ 5Subtract 4: 2x ≥ 10; Divide by 2: x ≥ 5
  2. x ≤ 3Subtract 4: 4x ≤ 12; Divide by 4: x ≤ 3
  3. x ≥ 3Subtract 5: 3x ≥ 9; Divide by 3: x ≥ 3
  4. x ≤ 5Subtract 2: 2x ≤ 10; Divide by 2: x ≤ 5
  5. x ≥ 7Subtract 4: 4x ≥ 28; Divide by 4: x ≥ 7
  6. x ≥ 5Subtract 5: 2x ≥ 10; Divide by 2: x ≥ 5