Page 48 - 新思维数学学生用书8 样章

2.4 Factorising

Think like a mathematician

7 In pairs or a small group, discuss what Zara and Sofia say.

I think the highest I think the highest
common factor of common factor of
2
6x and 9x is 3. 6x and 9x is 3x.
2

a What do you think? Explain your answer.
b What is the highest common factor of
i 8y and 4y ii 12p and 15p iii 4ab and 5a?
2
2

8 Each expression on a yellow card has been factorised to give an
expression on a blue card.
Match each yellow card with the correct blue card.

A 6x + 12x B 6x + 15x C 6x + 9x D 6x + 18x
2
2
2
2
i 3x(2x + 5) ii 6x(x + 3) iii 6x(x + 2) iv 3x(2x + 3)

9 Factorise each of these expressions.
a 3x + x b 6y − 12y c 3b + 9b 2 d 12n − 15n 2
2
2
e 18y − 9x f 12y + 9x g 8xy − 4y h 15z + 10yz
10 Copy and complete these factorisations.
a 2x + 6y + 8 = 2(x + 3y + ) b 4y − 8 + 4x = 4(y − + x)
c 9xy + 12y − 15 = 3(3xy + − 5) d 5x + 2x + xy = x(5x + + )
2
e 9y − y − xy = y( − − ) f 3y − 9y + 6xy = 3y( − + )
2
2

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