Solve: 3x + 7 = 22
Step 1 Subtract 7 from both sides
3x + 7 - 7 = 22 - 7
3x = 15
Step 2 Divide both sides by 3
3x ÷ 3 = 15 ÷ 3
x = 5
Check Substitute back
3(5) + 7 = 15 + 7 = 22 ✓
Answer:
x = 5
This study notes covers Worked Example 1: Two-Step Equation within Linear Equations for GCSE Mathematics. Revise Linear Equations in Algebra for GCSE Mathematics with 16 exam-style questions and 12 flashcards. This is a high-frequency topic, so it is worth revising until the explanation feels precise and repeatable. It is section 3 of 5 in this topic. Use this study notes to connect the idea to the wider topic before moving on to questions and flashcards.
Practice questions for Linear Equations
What is the solution to 3x = 12?
Solve x + 7 = 15
Quick recall flashcards
Golden Rule of solving equations
Whatever you do to one side, you MUST do to the other side to keep the equation balanced.
What does 'solving an equation' mean?
Finding the value of the unknown (e.g. x) that makes the equation true. You isolate x by doing the same operation to both sides.