Page 26 - 新思维数学活动用书8 样章

2.4 Factorising

3 Copy and complete these factorisations.
All the numbers you will need are in the cloud. 2 3
a 2x + 8 = 2(x + ) b 3x + 9 = 3(x + ) 4 5

c 5y − 25 = 5(y − ) d 7y − 14 = 7( − )
4 Expand these brackets.
a 3(2x + 1) = 6x + b 4(3x + 1) = +

c 2(5y − 1) = − d 6(4y − 1) = −
5 Use your answers to Question 4 to factorise these expressions.
a 6x + 3 = b 12x + 4 =

c 10y − 2 = d 24y − 6 =

Practice

6 Copy and complete these factorisations.
All the numbers you will need are in the cloud.
a 4x + 6 = 2(2x + ) b 6x − 15 = 3(2x − ) 2 3 4
5 7 9
c 35y + 10 = 5( y + ) d 28y − 63 = 7( y − )
7 Factorise each expression.
Make sure you use the highest common factor.
a 5z + 15 b 2y − 14 c 20x + 4 d 9w − 3

e 6v + 8 f 14a − 21 g 12 − 6b h 14 + 21d
8 Each expression on a grey card has been factorised to give an expression on a
white card.
Match each grey card with the correct white card.

A 3x + 15x i 5x(3x + 1)
2
B 4x + 12x ii 2x(2x + 5)
2
C 4x + 10x iii 3x(x + 5)
2
D 15x + 5x iv 4x(x + 3)
2
9 Factorise each expression.
a 7m + m b 5a − 15a c t + 9t
2
2
2
d 8h − 4h e 3y + 12y f 12y − 16y
2
2
2
g 16e + 8e h 15e + 6i
2
10 Copy and complete these factorisations.
a 14cd − 7c = 7c(2d − ) b 12a + 8ab = 4a( + 2b)
c 21g + 15gh = 3g( + ) d 30w − 15tw = 15w( − )

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