© Pearson Education Limited 2009 1

Chapter 17 AnswersChapter 17 Answers 1 (a) (c) trapezium

(b) (d) parallel

2 A = (2,1) B = (7,5) C = (1,6) D = (4,6)

E = (–2, 1) F = (1,4) G = (–1, –2) H = 8,–3)

3

4 (a) y = 0 (b) x = 0

5 (a) (b)

(c) All go through the origin. They get closer to the y axis.

(d) The lines get steeper.

6 (a) (b)

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(c) They are all parallel. They have the same gradient (steepness).

7 (a) m = 20 (b) m = –3 (c) m = –2 (d) m = –7

8 (a) y = 4x + 9, m = 4 (b) y = 4x + 6, m = 4

(c) y = 2x + 4, m = 2 (d) y = x + 1, m = 1

9 (c), (e) and (f)

10 (a) y = x – 2 , m = 1, c = –2

(b) y = 3x + 6, m = 3, c = 6

(c) y = 3x m = 3 c = 0

(d) y = –4x + 2, m = –4 c = 2

(e) y = –4x + 3, m = –4 c = 3

(f) y = x – 7, m = 1 c = –7

(g) y = –7x + 4 m = –7 c = 4

(h) y = 0 m = 0 c = 0

(i) y = –2x – 3 m = –2 c = –3

(j) y = x + 1 m = 1 c = 1

11 (a) y =

5

2x –

7

2 (b) y =

4

3x +

8

3 (c) y =

7

5x –

8

5

(d) y = –

2

5x –

1

2 (e) y = –

2

3x +

1

2 (f) y = –

2

3x –

1

3

(g) y = –

4

5x –

3

5 (h) y = –

1

6x +

1

2 (i) y = –

4

5x +

3

5

12 i. (a)

x –3 –2 –1 0 1 2 3

y 9 4 1 0 1 4 9

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(b)

(c)

(d) The line of symmetry is x = 0

ii. (a)

x –3 –2 –1 0 1 2 3

y 0 –2 –2 0 4 10 18

(b)

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(c)

(d) The line of symmetry is x = –1.5

iii. (a)

x –4 –3 –2 –1 0 1 2 3

y 13 7 3 1 1 3 7 13

(b)

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(c)

(d) The line of symmetry is x = –0.5.

13

x = –1.5 or x = 2

14 (a)

(b) x = –1 and x = 4

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15 (a)

litres 0 5 10

pints 0 8.75 17.5

(b) Approximately 4.5 (4.5714)

16 (a)

m2 0 2 2.5 5

cm2 0 20 000 25 000 50 000

(b)

(c) Linear

(d) 37 000 cm2