八年级下：分式的乘除法同步练习
一、判断正误（对的打“√”,错的打“×”）(每小题 3 分,共 15 分)
x 2 + y 2 1.
x + y =x+y （ ）
2. （p －q ）2÷（q －p ）2=1（
）
x 8 3.
x 4 = x 2（ ）
4. 4(m + n )2 9(m - n )2 = 2(m + n ) （ ） 3(m - n )
5.
a + m = a （m ≠0）（ ）
b + m b
二、请你填一填(每小题 4 分,共 32分)
1. 把一个分式的分子与分母的
约去，叫做分式的约分;在
分式
x 2 y + xy 2 中，分子与分母的公因式是
. 2xy 2. 将下列分式约分：(1 )
(a - b )2 = .
(b - a )2 x 5 8x 2 = ; (2) 7m 2n - 35mn 2 = ;(3) 3. 计算 2a 3b ÷ 6ab 2 = .
4. 计算 c 3b 2 c 2
a -
b ÷ ab - a 2 = . a 2 + ab a 2b 2 - a 4
5. 计算(- x
)2·(- x 2 )3÷(- x )4= . y y 3
y
6. 已知 x －y=xy,则 1 － 1 =
. x
y
7. 若 1 ∶ 1 ∶ 1 =2∶3∶4,则 a∶b∶c= .
a b c
8.若x =y=z,则x +y = .
4 4
5 x - 2 y + 3z
三、细心算一算:(每小题 10 分,共 40 分)
1. 计算：(1)a 2 -b2
÷（a－b）2（2）（2x）2·（3y）3÷（1 ab 3y 4x 4
xy）
2.. 先化简，再求值：3a2-ab
9a2- 6ab +b2,其中 a =－8,b = 1.
2
1 3.若
x
1
－
y
=3, 求
2x + 3xy - 2 y
x - 2xy -y
的值.
四、用数学眼光看世界(10 分)
甲队在 n 天内挖水渠 a 米，乙队在 m 天内挖水渠 b 米，如果两队同时挖水渠，要挖 x 米，需要多少天才能完成？（用代数式表示）
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At the end, Xiao Bian gives you a passage. Minand once said, "people who learn to learn are very happy people.". In every wonderful life, learning is an eternal theme. As a professional clerical and teaching position, I understand the importance of continuous learning, "life is diligent, nothing can be gained", only continuous learning can achieve better self. Only by constantly learning and mastering the latest relevant knowledge, can employees from all walks of life keep up with the pace of enterprise development and innovate to meet the needs of the market. This document is also edited by my studio professionals, there may be errors in the document, if there are errors, please correct, thank you!。