Edexcel IGCSE Maths

Revision Notes

2.9.1 Substitution

What is substitution?

  • Substitution is where we replace letters in a formula with their values
  • This allows you to find one other value that is in the formula

How do we substitute?

  • Write down the FORMULA if not clearly stated in question
  • SUBSTITUTE the numbers given – use ( ) around negative numbers
  • SIMPLIFY if you can
  • REARRANGE if necessary – it is usually easier to substitute first
  • Do the CALCULATION – use a calculator if allowed

Worked Example

Substitution WE 1, downloadable IGCSE & GCSE Maths revision notes


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