year 8 maths

70 Chapter 2 Equations 2
Exercise 2B
REVISION
UNDERSTANDING AND FLUENCY
1–6, 7–9(½) 2–4, 5–10(½)
6–10(½)
1 For each of the following equations add 4 to both sides to obtain an equivalent equation.
a 3x = 10 b 7 + k = 14 c 5 = 2x
2 For each equation fill in the blank to get an equivalent equation.
a 5x = 10
b 10 − 2x = 20
+2 +2
+5 +5
5x + 2 = –– 15 − 2x = ––
c 3q + 4 = ––
−4
3q = 12
−4
3 Consider the equation 4x = 32 .
a Copy and complete the following working.
4x = 32
÷4 ÷4
x = ––
b What is the solution to the equation 4x = 32 ?
d 7z + 12 = 4z + 10
−10
7z + 2 = ––
4 To solve the equation 10x + 5 = 45 , which of the following operations would you first apply to
both sides?
A divide by 5 B subtract 5 C divide by 10 D subtract 45
−10
Example 4
5 For each equation, show the result of applying the given operation to both sides.
a 10 + 2x = 30 [−10] b 4 + q = 12 [−2] c 13 = 12 − q [+5]
d 4x = 8 [×3] e 7p = 2p + 4 [+6] f 3q + 1 = 2q + 1 [−1]
6 Copy and complete the following to solve the given equation systematically.
a 10x = 30
b q + 5 = 2
÷10 ÷10
−5
−5
x = –– –– = ––
c 4x + 2 = 22
d 30 = 4p + 2
−2
−2
−2
−2
4x = ––
–– = ––
÷4 ÷4
□ □
–– = ––
–– = ––
e 20 − 4x = 8
−20
−4x = −12
÷−4 ÷ −4
x = –– –– = ––
f p ÷ 3 + 6 = 8
−20
−6
−6
p ÷ 3 = 2
□ □
Example 5a
7 Solve the following equations systematically.
a a + 5 = 8 b t × 2 = 14
c 7 = q − 2 d 11 = k + 2
e 19 = x + 9 f −30 = 3h
g −36 = 9l
h g ÷ 3 = −3
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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