EDEXCEL GCSE MATHS · FOUNDATION & HIGHER
Exam Practice: Equations
Equations · Algebra · Lesson 3 of 7 · 16 marks · 25 minutes
Name Date
Answer all questions. Show your working. Questions 1 to 4 are non-calculator.
Question 1 NON-CALCULATOR [2 marks]
Solve 7x + 4 = 3x − 12
Question 2 NON-CALCULATOR [3 marks]
Solve 4(3 − 2x) = 2(x + 11)
Question 3 NON-CALCULATOR [3 marks]
Solve (5x − 2)/3 = (x + 4)/2
Question 4 NON-CALCULATOR [4 marks]
The diagram shows a triangle. The sizes of its angles, in degrees, are 2x + 10, 3x − 5 and x + 25. Work out the size of the largest angle.
Question 5 CALCULATOR [4 marks]
Amy is 3 times as old as Ben. In 8 years' time, Amy will be twice as old as Ben. How old is Amy now?
Answers
Check your answer only once you have written one.
Question 1 [2 marks]
4x = −16, so x = −4
▸ 4x = −16, or a correct first step collecting x terms or numbers M1
▸ x = −4 A1
Question 2 [3 marks]
12 − 8x = 2x + 22, so −10 = 10x and x = −1.
▸ Both brackets expanded correctly M1
▸ Correctly collects x terms on one side and numbers on the other M1
▸ x = −1 A1
Question 3 [3 marks]
2(5x − 2) = 3(x + 4), so 10x − 4 = 3x + 12, 7x = 16 and x = 16/7.
▸ Multiplies both sides to clear the fractions, e.g. 2(5x − 2) = 3(x + 4) M1
▸ 7x = 16 M1
▸ x = 16/7 (or 22/7) A1
Question 4 [4 marks]
(2x + 10) + (3x − 5) + (x + 25) = 180, so 6x + 30 = 180, 6x = 150 and x = 25. The angles are 60°, 70° and 50°. The largest angle is 70°.
▸ Sets the sum of the angles equal to 180 P1
▸ 6x + 30 = 180 P1
▸ x = 25 P1
▸ 70° A1
Question 5 [4 marks]
Let Ben be b. Amy is 3b. In 8 years: 3b + 8 = 2(b + 8), so 3b + 8 = 2b + 16 and b = 8. Amy is 24.
▸ Ben = b and Amy = 3b, or equivalent P1
▸ 3b + 8 = 2(b + 8) P1
▸ b = 8 P1
▸ Amy is 24 A1