Rearranging Formulae

MathematicsAQAEdexcelGCSEUnit: Algebra
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The basics

Making a Letter the Star

Making a Letter the Star

You know v = u + at for motion. But what if you know v and need to find a? You need to "make a the subject" - rearrange so a is alone on one side. It's like solving an equation, but with letters instead of numbers!
What is the 'subject' of a formula?: The variable that stands alone on one side of the equals sign. In v = u + at, v is the subject.
Key terms

Mathematics glossary

What is the 'subject' of a formula?
The variable that stands alone on one side of the equals sign. In v = u + at, v is the subject.
What does 'rearranging a formula' produce?
An equivalent formula expressing a different variable as the subject. E.g. v = u + at rearranges to a = (v − u)/t.
Spotlight
The Method: Reverse BIDMAS

Order to undo: Addition/Subtraction first → Multiplication/Division → Powers/Roots

Now try it yourself

Quiz · Question 1 of 14

Make b the subject of the formula: a = b + c

Tap an answer to check it

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