GCSE · Formulae & rearranging

Rearranging formulaeExam-style questions

Why changing the subject is solving-an-equation in disguise, why operations must be undone in reverse order (onion peeling), and how fractions, squares and roots come apart.

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14 questions · GCSE (Higher) level · mark scheme and worked solution on each · no sign-up to try

DifficultyAll Level 1 Level 2 Level 3 Level 4 Level 5

1
Tara rearranges the formula $y = \dfrac{3w + 2}{5}$ to make $w$ the subject.

Her working is shown below.

$5y = 3w + 2$

$5y + 2 = 3w$

$w = \frac{5y + 2}{3}$

Tara's answer is not correct.
(a) What mistake has Tara made?

(1 mark)
(b) Factorise fully $14p^2q + 21pq$

(2 marks)
Level 3 · 3 marksTry it
2
Make $x$ the subject of $\;y = 4x - 7$
Level 3 · 2 marksTry it
3
Make $t$ the subject of $\;v = u + at$
Level 3 · 2 marksTry it
4
Make $m$ the subject of $\;E = mgh$
Level 3 · 2 marksTry it