Rearranging formulae (AQA GCSE Maths): Flashcards

Subject of a formula

Single letter by itself on one side of equals sign

Subject in $P = 2l + 2w$

$P$

Two-step method to find missing values

1. Substitute known values 2. Solve equation

Key principle when rearranging formulae

Do the same operation to both sides

How to isolate target letter when rearranging

Use inverse operations to move other terms

How to deal with fractions when rearranging

Multiply both sides by the denominator

How to deal with brackets when rearranging

Expand the brackets first, then rearrange

How to deal with negative terms when rearranging

Add the negative term to both sides to make positive

Make $p$ the subject: $N = 2p + 3q^2$

$p = \frac{N - 3q^2}{2}$

Make $h$ the subject: $A = \frac{1}{2}bh$

$h = \frac{2A}{b}$