year 8 maths

1D
Multiplying and dividing terms
19
b 3xy × 5xz
c
d
= 3 × x × y × 5 × x × z
= 3 × 5 × x × x × y × z
Write the expression with multiplication signs and
bring the numbers to the front.
= 15x 2 yz Simplify, remembering that x × x = x 2 .
10ab
15bc = 2 10 × a × b
3
15 × b × c
= 2a
3c
18x 2 y 9
8xz
= 18 × x × x × y
4
8 × x × z
= 9xy
4z
Write the numerator and denominator in full, with
multiplication signs. Cancel any common factors and
remove the multiplication signs.
Write the numerator and denominator in full,
remembering that x 2 is x × x . Cancel any common
factors and remove the multiplication signs.
Exercise 1D
REVISION
UNDERSTANDING AND FLUENCY
1–5, 6(½), 7, 8 4, 5–6(½), 7, 8(½) 6(½), 7, 8(½)
1 Which is the correct way to write 3 × a × b × b ?
A 3ab B 3ab 2 C ab 3 D 3a 2 b
2 Simplify these fractions.
12
5
12
15
a
b
c
d
20
15
8
25
3 Which one of these is equivalent to a × b × a × b × b ?
A 5ab B a 2 b 3 C a 3 b 2 D (ab) 5
4 Write these without multiplication signs.
a 3 × x × y
b 5 × a × b × c
c 12 × a × b × b
d 4 × a × c × c × c
Example 7a
Example 7b
5 Simplify the following.
a 7d × 9 b 5a × 2b
c 3 × 12x d 4a × 2b × cd
e 3a × 10bc × 2d f 4a × 6de × 2b
6 Simplify the following.
a 8ab × 3c b a × a
c 3d × d d 5d × 2d × e
e 7x × 2y × x f 5xy × 2x
g 4xy × 2xz
h 4abc × 2abd
i 9ab × 2a 2 j −3xz × (−2z)
k −5xy × 2yz l 4xy 2 × 4y
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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