Linear Equations

MathematicsAQAEdexcelGCSEUnit: Algebra
Free taster
5 of 6 sections open
The basics

The Golden Rule of Equations

The Golden Rule of Equations

Think of an equation like a perfectly balanced scale. Whatever you do to one side, you MUST do to the other side to keep it balanced. Want to remove the +7? Subtract 7 from BOTH sides. Want to get rid of the "times 3"? Divide BOTH sides by 3. The goal: get x completely alone on one side.
Solving linear equations - balance method, step-by-step solve, inverse operations, unknowns on both sides
Exam tip

Earn the mark scheme marks

Common Mistakes to Avoid

  • WRONG: 3x + 7 = 22, so x = 22/3 + 7 (Forgetting to deal with +7 first)
  • WRONG: Doing an operation to only ONE side (Must do the same to BOTH sides)
  • RIGHT: Always do inverse operations in reverse order of BIDMAS

Now try it yourself

Quiz · Question 1 of 16

What is the solution to 3x = 12?

Tap an answer to check it

Revise every Mathematics topic, free during alpha

Linear Equations is one of 127 topics on PrepWise — all aligned to your exam board.

Start revising free →