Maths Library

Linear inequalities: Year 9 maths

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

Linear inequalities is taught in Year 9 (age 13 to 14, KS3) 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 National Curriculum for England. Check wording and codes against the official document.

  • Solve simple linear inequalities in one variable and represent solutions on a number line.

Sample sheet and answers

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

Linear inequalities

Year 9 maths

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

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