Page 23 - 新思维数学活动用书9 样章

2 Expressions and formulae

Practice

6 Simplify each expression.
a a × a 4 b b × b 5 c c × c d d ÷ d 4
7
5
3
8
2
y
e e ÷ e 2 f f ÷ f g g ( ) 4 h ( ) 7
8
8
6
i ( ) 8 j 4 j + 9 j 2 k 6k − 5k 3 l 4l + l − 8l 5
9
2
3
5
i
5
7 Simplify each expression.
a 3a × 2a 2 b 4b × 4b 4 c 6c × 6c 6 d 10e × e 5
2
3
6
6
e 16g ÷ 2g 4 f 9h ÷ 3h 3 g 10x 10 h 5x 5
9
12
2x 2 x
8 Which is the correct answer, A, B, C or D?
a Simplify 3a × 4a A 7a B 12a C 7a D 12a 6
2
6
5
3
5
b Simplify 4b × 5b A 20b B 20b C 9b D 9b 3
4
3
3
4
c Simplify 15c 6 A 3c B 10c C 3c D 10c 3
3
2
2
5c 3
d Simplify 9d 5 A 3d B 6d C 6d D 3d 4
5
4
5
3d
9 Look at these algebra cards.
a Simplify the expressions, then sort the cards into two groups.
Explain how you decided to sort the groups.
b Which card does not fit into either of the groups? Explain why this is.
x × 3x 3 9x ÷ x 9 2x × 3x 5 12x ÷ 4x 3
12
12
6
9x ÷ 3x 3 6x × x 3 3x × 2x 3
3
6
9
3 2
10 Sofia and Zara simplify the expression (2x ) . Read what they say.
I think the
answer is 4x .
5
I think the
answer is 4x .
6
a Who is correct, Sofia or Zara? Explain why.
b Simplify these expressions.
i (3x ) ii (4y ) iii (2z )
9 3
3 5
7 2

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