Page 29 - 新思维数学活动用书7 样章

2 Expressions, formulae and equations

Work out the total length of each arrangement of bricks. Give each

answer in its simplest form.
a b
? ?

c d
? ?

e f
? ?

7 Simplify each expression.
a a + a + a + a b 4b + 3b c 4c + 7c
d 2d + 3d + 4d e 6e + 6e + e f 10f + f + 4f

g 9g − 3g h 4h −3h 2 i 9i − i
2
j 8j + 2j − 4j k k + 6k − 3k l 12y − 4y − 7y 3
3
3
8 In an algebraic pyramid, you find the expression in each block by adding the expressions in the
two blocks below it.
Copy and complete these pyramids.
a b
15x

10x 7x
x 7x 3x 4x

9 Simplify these expressions by collecting like terms.
a 3x + 4x + 5y b 5z + 5z + 5a + a
c 3a + 4b + 4a + 5b d 4x + 5 + 3x + 2

e d + 1 + d + 1 f 5f − 3f + 12g − 3g
g 45 − 15 + 12w − w h 7x + 5y − 3x + y
i 8a + 6b − 4a − 5b j 4w + 3x + 7y − 2w − 3x + 13y
k 200a + 20g + 100 − 15g − 70

10 Write each expression in its simplest form.
a 4ab + 2ab + 3xy + 5xy b 3rd + 3rd + 5th + 6th
c 5tv + 6tv + 9jk − 5kj d 8ej + 7yh − 3je − 4hy
e 5v + 15rv − 2v + vr f 7un − 4nu + 11ef − 11fe

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