EDEXCEL GCSE MATHS · FOUNDATION & HIGHER
Exam Practice: Formulae
Formulae · Algebra · Lesson 4 of 7 · 14 marks · 25 minutes
Name Date
Answer all questions. Show your working. Questions 1 to 4 are non-calculator.
Question 1 NON-CALCULATOR [2 marks]
v = u + at. Work out the value of v when u = 12, a = −3 and t = 5.
Question 2 NON-CALCULATOR [2 marks]
Make t the subject of the formula v = u + at
Question 3 NON-CALCULATOR · SHOW THAT [2 marks]
Show that (x + 3)² − 9 ≡ x(x + 6)
Question 4 NON-CALCULATOR · HIGHER [4 marks]
Make a the subject of 3(a − 2) = ab + 5
Question 5 CALCULATOR [2 marks]
s = ut + ½at². Work out the value of s when u = 15, a = −9.8 and t = 2.
Question 6 CALCULATOR · HIGHER [2 marks]
The volume of a sphere is V = 4/3πr³. Make r the subject of the formula.
Answers
Check your answer only once you have written one.
Question 1 [2 marks]
v = 12 + (−3) × 5 = 12 − 15 = −3
▸ 12 + (−3) × 5, or −15 seen M1
▸ −3 A1
Question 2 [2 marks]
v − u = at, so t = (v − u)/a
▸ v − u = at, or a correct first step M1
▸ t = (v − u)/a A1
Question 3 [2 marks]
(x + 3)² − 9 = x² + 6x + 9 − 9 = x² + 6x = x(x + 6)
▸ (x + 3)² expanded to x² + 6x + 9 M1
▸ Correctly simplified to x(x + 6), or both sides shown equal to x² + 6x A1
Question 4 [4 marks]
3a − 6 = ab + 5, so 3a − ab = 11, a(3 − b) = 11 and a = 11/(3 − b).
▸ Expands the bracket: 3a − 6 M1
▸ Collects the a terms on one side: 3a − ab = 11 M1
▸ Factorises: a(3 − b) = 11 M1
▸ a = 11/(3 − b) A1
Question 5 [2 marks]
s = 15 × 2 + ½ × (−9.8) × 2² = 30 − 19.6 = 10.4
▸ 15 × 2 + ½ × (−9.8) × 2², or 30 and −19.6 seen M1
▸ 10.4 A1
Question 6 [2 marks]
3V = 4πr³, so r³ = 3V/4π and r = ∛(3V/4π).
▸ r³ = 3V/4π M1
▸ r = ∛(3V/4π) A1