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Class 7 Maths — Solving equations

Solve a linear equation in one variable by keeping both sides balanced.

Name: ________________________

Before you start

Two mystery boxes and some weights, and the beam is level. See how much you can take away without it moving.

517

Take the 5 off both sides and the two boxes stand against what is left; one box is half of that. The scale has just walked you through the whole solution without a line of working.

  1. 1.2x + 1 = x + 9. What is x?

  2. 2.What is the right first move to solve 7x = 56?

    • a) Subtract 7 from both sides
    • b) Multiply both sides by 7
    • c) Divide both sides by 7
    • d) Add 7 to both sides

  3. 3.2x + 3 = 11. What is x?

  4. 4.3x = 21. What is x?

  5. 5.3x - 4 = 2x + 6. What is x?

  6. 6.5x - 7 = 18. What is x?

  7. 7.Put these steps in the right order to solve 3x + 4 = 19.

    • Divide both sides by 3
    • x = 5
    • 3x = 15
    • Subtract 4 from both sides

  8. 8.I think of a number, double it and add 5. The answer is 17. What was my number?

Answer key — Class 7 Maths — Solving equations

  1. 1. 8
  2. 2. c) Divide both sides by 7
  3. 3. 4
  4. 4. 7
  5. 5. 10
  6. 6. 5
  7. 7. 1. Subtract 4 from both sides 2. 3x = 15 3. Divide both sides by 3 4. x = 5
  8. 8. 6