Cambridge Essentials Mathematics Core 9 A3.2 Answers

A3.2 Answers

1 a £4.80 b £8.00 c £16.00 d £1.20

2 a £9.98 b £59.88 c £179.64 d £499

3 x 1 2 3 4 5 6 y 0.5 1 1.5 2 2.5 3

x x a x → b y = 2 2

Original Material © Cambridge University Press 2010 1 Cambridge Essentials Mathematics Core 9 A3.2 Answers

4 a 27.6 litres b 515.2 litres c 6.9 litres

5 a £17.63 b £21.53 c 18.6 metres

6 a Yes. When x increases by 1, y increases by 7.

b Yes. When x increases by 1, y increases by 2.5.

c No. When x increases by 8, y increases by 1, except for when x is 10.

7 a Number of Swiss francs = 2.06  number of pounds Sterling (or f = 2.06p)

Pounds 1 2 5 10 40 60 Swiss francs 2.06 4.12 10.3 20.6 82.4 123.6

c £50 d £25.24 e 72.1 Swiss francs f 2 060 000 Swiss francs

k 0 4 8 12 16 20 m 0 2.5 5 7.5 10 12.5

c 6 kilometres d 6 miles

9 c: p is not in direct proportion to q.

10 a y-value increases by 4 each time b y = 4x

11 (3, 4), (5, 19)

1 3 12 a y = 2x b y = x c y = x 2 2

13 a y = 5x b 45 c 17 d 6 e 2.4

q 14 a p = b 8 c 6.4 d 28 e 15 2

15 a y = 10x b 14 c 2.5

d y = 10x e Students’ checking of answers