GCSE Maths · Topic guide

Inequalities

An inequality is a statement comparing two expressions with greater than, less than, or their or-equal-to versions, rather than stating they are exactly equal. In GCSE Algebra, students solve linear inequalities using the same steps as for equations, show solution sets on a number line, and list integer solutions, remembering to reverse the sign when multiplying or dividing by a negative number.

Grade 4-5 (Foundation & Higher)AlgebraEdexcelAQAOCR

Before you start

Make sure you're comfortable with these topics first:

Method

  1. Treat the inequality like an equation: do the same operation (add, subtract, multiply, divide) to both sides to isolate the letter.
  2. If you multiply or divide both sides by a negative number, reverse the direction of the inequality sign.
  3. To solve a double inequality, such as -3 < 2x + 1 <= 9, apply each operation to all three parts at once.
  4. To list integer solutions, write out the whole numbers that satisfy the inequality, checking carefully whether the boundary values are included (<=, >=) or excluded (<, >).
  5. To show a solution on a number line, use an open circle for < or > since the boundary is not included, and a filled circle for <= or >= since it is included, then draw a line or arrow in the direction of the solutions.
  6. Check your answer by substituting a value from your solution set back into the original inequality.

Worked example

Solve the inequality 3(x - 2) >= 2x + 4.

  1. Expand the bracket: 3x - 6 >= 2x + 4.
  2. Subtract 2x from both sides: x - 6 >= 4.
  3. Add 6 to both sides: x >= 10.

Practice questions

Try each question, then tap to reveal the answer.

Exam-style questions

Written in the style of a GCSE Maths exam paper, with a full mark scheme.

Q1[2 marks]

Solve the inequality 6x - 5 <= 3x + 10.

Q2[3 marks]

n is an integer such that -4 <= n < 3. (a) List all the possible values of n. (2) (b) Write down the largest possible value of n. (1)

Q3[4 marks]

Solve the inequality -5 < 3x - 2 <= 10, and describe how the solution set would be shown on a number line.

See real past-paper questions on inequalities, organised by topic with official mark schemes

Free printable worksheet

Want more practice on paper? Download the inequalities worksheet pack - 9 pages of exam-style questions with a full mark scheme. No sign-up, no email wall - just the PDF, free for personal and classroom use.

Build a full practice pack.

This topic is one of hundreds in the library - pick the ones a student needs and generate a printable PDF in minutes.