year 8 maths

7B
Using rules, tables and graphs to explore linear relationships
407
Exercise 7B
UNDERSTANDING AND FLUENCY
1–5 3, 4–5(½)
4–5 (½)
1 For the rule y = 2x + 3 find the y -coordinate for these x -coordinates.
a 1 b 2 c 0 d −1
e −5 f −7 g 11 h −12
2 Write the missing number in these tables for the given rules.
a y = 2x b y = x − 3 c y = 5x + 2
x 0 1 2 3
y 0 4 6
x −1 0 1 2
y −4 −3 −1
x −3 −2 −1 0
y −8 −3 2
3 Complete the graph to form a straight line from the given rule and table. Two points have been plotted
for you.
y = 2x − 2
y
x −2 −1 0 1 2
y −6 −4 −2 0 2
−3 −2
3
2
1
−1
O
−1
−2
−3
−4
−5
−6
1
2 3
x
Example 2
4 For each rule construct a table like the one shown here.
x −3 −2 −1 0 1 2 3
y
a y = x + 1 b y = x − 2 c y = 2x − 3 d y = 2x + 1
e y = −2x + 3 f y = −3x − 1 g y = −x h y = −x + 4
Example 3
5 Decide if the given points lie on the graph with the given rule.
a Rule: y = 2x Points: i (2, 4) and ii (3, 5)
b Rule: y = 3x − 1 Points: i (1, 1) and ii (2, 5)
c Rule: y = 5x − 3 Points: i (−1, 0) and ii (2, 12)
d Rule: y = −2x + 4 Points: i (1, 2) and ii (2, 0)
e Rule: y = 3 − x Points: i (1, 2) and ii (4, 0)
f Rule: y = 10 − 2x Points: i (3, 4) and ii (0, 10)
g Rule: y = −1 − 2x Points: i (2, −3) and ii (−1, 1)
Cambridge Maths NSW
Stage 4 Year 8 Second edition
ISBN 978-1-108-46627-1 © Palmer et al. 2018
Cambridge University Press
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