八年级数学《分式》练习
题
快递公司问题件快递公司问题件货款处理关于圆的周长面积重点题型关于解方程组的题及答案关于南海问题
一、选择题
1.下列各式中,相等关系成立的是 ( )
nmmn,mnmn,,333623xxx,,xxx,xxx,2xxx,, A. B. C. D.
35213633,,2133xxx(),()(),,,,xxx(0.1)1010,2xxx,,2.下列运算:?1;?2;?3;?4 结果正确的是 ( )
A.?1,?2 B.?2,?4 C.?2,?3 D.?2,?3,?4 3.下列计算中结果正确的是 (
1,22,,624()(),,,,aaaababa(31)3,,,22aa,,4A. B. C. D.
322733,325,()aaa,(),,aaaaaa,,4.设a?0,以下运算结果:?1;?2;?3;?4
,,23(),,,aaa,其中正确的是( )
A.?1,?2 B.?1,?3 C.?2,?4 D.?2,?3
32()(3),,,abcab45.计算,正确的结果应是( )
911922acacacac4444A. B. C. D.
2322mn828ababb,,76.已知,那么m,n的取值为 ( )
A.m=4,n=3 B.m=4,n=1 C.m=1,n=3 D.m=2,n=3
7355332537xy28212(7)xyxyyxy,,7.与一个多项式的积为,则这个多项式为 ( )
222243xy,43xyxy,A. B.
2232244314xyxy,,437xyxy,, C. D.
422633330,,,,xxx(),,,,aaa()xxx,,,18.下面有四个式子:(1);(2);(3);
234234abcabc,,0(4);其中正确的个数有( )
23222[()3()](),,,,,aaaa,结果等于( ) A.3个 B.2个 C.1个 D.0个
323242429.计算:,,aa3aa,3,,aa3,,aa A. B. C. D. 10.在下面的式子中,正确的是 ( )
3262362433()(),,,,aaaaaa,,aaa,,aaa,,A. B. C. D. 二填空题
105311.(-x)?( )=x=( )?(-x)
-+n1mn 12.a?( )=a
223213.( )?(-3xyz)=4xy
714.4?( )=32
2 3215.(m+n)(m-n)?( )=-(m+n)
22216.(m+n)(m-n)?( )=-(m+n)
143432,,,,6()xyzxyz317.
522n()[()]()ababab,,,,18.=
113242332422()()axaxaxax,,,,234319.=
132ab37,18ab220.如果代数式A除以得,则A=
71093314xyMxy,,,421.如果,则M=
mn432252axyxyxy()(3)4,,22.如果,则a= ,m= ,n=
aa,221a,a3,m3,3,,,2723.已知,则 ,= ,
24.计算:
52335333[()][()],,,yyy1(1)2,,, (1) (2);
1212mm,25(),8293(2)[(2)](2)(2),,,,,,,aaaa(3)5 (4)
1311147382632ababababab,,,,,,,,4,()()24293
25.先化简,再求值:
mn241mn,,36,92,,26.若3,求的值