合并同类项的数学题

问题描述:

合并同类项的数学题

3.3ab-4ab+8ab-7ab+ab=______.
4.7x-(5x-5y)-y=______.
5.23a3bc2-15ab2c+8abc-24a3bc2-8abc=______.
6.-7x2+6x+13x2-4x-5x2=______.
7.2y+(-2y+5)-(3y+2)=______.
11.(2x2-3xy+4y2)+(x2+2xy-3y2)=______.
12.2a-(3a-2b+2)+(3a-4b-1)=______.
13.-6x2-7x2+15x2-2x2=______.
14.2x-(x+3y)-(-x-y)-(x-y)=______.
16.2x+2y-[3x-2(x-y)]=______.
17.5-(1-x)-1-(x-1)=______.
18.( )+(4xy+7x2-y2)=10x2-xy.
19.(4xy2-2x2y)-( )=x3-2x2y+4xy2+y3.
21.已知A=x3-2x2+x-4,B=2x3-5x+3,计算A+B=______.
22.已知A=x3-2x2+x-4,B=2x3-5x+3,计算A-B=______.
23.若a=-0.2,b=0.5,代数式-(|a2b|-|ab2|)的值为______.
25.一个多项式减去3m4-m3-2m+5得-2m4-3m3-2m2-1,那么这个多项式等于______.
26.-(2x2-y2)-[2y2-(x2+2xy)]=______.
27.若-3a3b2与5ax-1by+2是同类项,则x=______,y=______.
28.(-y+6+3y4-y3)-(2y2-3y3+y4-7)=______.
29.化简代数式4x2-[7x2-5x-3(1-2x+x2)]的结果是______.
30.2a-b2+c-d3=2a+( )-d3=2a-d3-( )=c-( ).
31.3a-(2a-3b)+3(a-2b)-b=______.
32.化简代数式x-[y-2x-(x+y)]等于______.
33.[5a2+( )a-7]+[( )a2-4a+( )]=a2+2a+1.
34.3x-[y-(2x+y)]=______.
35.化简|1-x+y|-|x-y|(其中x<0,y>0)等于______.
36.已知x≤y,x+y-|x-y|=______.
37.已知x<0,y<0,化简|x+y|-|5-x-y|=______.
38.4a2n-an-(3an-2a2n)=______.
39.若一个多项式加上-3x2y+2x2-3xy-4得
2x2y+3xy2-x2+2xy,
则这个多项式为______.
40.-5xm-xm-(-7xm)+(-3xm)=______.
41.当a=-1,b=-2时,
[a-(b-c)]-[-b-(-c-a)]=______.
43.当a=-1,b=1,c=-1时,
-[b-2(-5a)]-(-3b+5c)=______.
44.-2(3x+z)-(-6x)+(-5y+3z)=______.
45.-5an-an+1-(-7an+1)+(-3an)=______.
46.3a-(2a-4b-6c)+3(-2c+2b)=______.
48.9a2+[7a2-2a-(-a2+3a)]=______.
50.当2y-x=5时,5(x-2y)2-3(-x+2y)-100=______.
(二)选择
[ ]
A.2;
B.-2;
C.-10;
D.-6.
52.下列各式中计算结果为-7x-5x2+6x3的是 [ ]
A.3x-(5x2+6x3-10x);
B.3x-(5x2+6x3+10x);
C.3x-(5x2-6x3+10x);
D.3x-(5x2-6x3-10x).
53.把(-x-y)+3(x+y)-5(x+y)合并同类项得 [ ]
A.(x-y)-2(x+y);
B.-3(x+y);
C.(-x-y)-2(x+y);
D.3(x+y).
54.2a-[3b-5a-(2a-7b)]等于 [ ]
A.-7a+10b;
B.5a+4b;
C.-a-4b;
D.9a-10b.
55.减去-3m等于5m2-3m-5的代数式是 [ ]
A.5(m2-1);
B.5m2-6m-5;
C.5(m2+1);
D.-(5m2+6m-5).
56.将多项式2ab-9a2-5ab-4a2中的同类项分别结合在一起,应为 [ ]
A.(9a2-4a2)+(-2ab-5ab);
B.(9a2+4a2)-(2ab-5ab);
C.(9a2-4a2)-(2ab+5ab);
D.(9a2-4a2)+(2ab-5ab).
57.当a=2,b=1时,-a2b+3ba2-(-2a2b)等于 [ ]
A.20;
B.24;
C.0;
D.16.
中,正确的选择是 [ ]
A.没有同类项;
B.(2)与(4)是同类项;
C.(2)与(5)是同类项;
D.(2)与(4)不是同类项.
59.若A和B均为五次多项式,则A-B一定是 [ ]
A.十次多项式;
B.零次多项式;
C.次数不高于五次的多项式;
D.次数低于五次的多项式.
60.-{[-(x+y)]}+{-[(x+y)]}等于 [ ]
A.0;
B.-2y;
C.x+y;
D.-2x-2y.
61.若A=3x2-5x+2,B=3x2-5x+6,则A与B的大小是
[ ]
A.A>B;
B.A=B;
C.A<B;
D.无法确定.
62.当m=-1时,-2m2-[-4m2+(-m2)]等于 [ ]
A.-7;
B.3;
C.1;
D.2.
63.当m=2,n=1时,多项式-m-[-(2m-3n)]+[-(-3m)-4n]等于 [ ]
A.1;
B.9;
C.3;
D.5.
[ ]
65.-5an-an-(-7an)+(-3an)等于 [ ]
A.-16an;
B.-16;
C.-2an;
D.-2.
66.(5a-3b)-3(a2-2b)等于 [ ]
A.3a2+5a+3b;
B.2a2+3b;
C.2a3-b2;
D.-3a2+5a-5b.
67.x3-5x2-4x+9等于 [ ]
A.(x3-5x2)-(-4x+9);
B.x3-5x2-(4x+9);
C.-(-x3+5x2)-(4x-9);
D.x3+9-(5x2-4x).
[ ]
69.4x2y-5xy2的结果应为 [ ]
A.-x2y;
B.-1;
C.-x2y2;
D.以上答案都不对.
(三)化简
70.(4x2-8x+5)-(x3+3x2-6x+2).
72.(0.3x3-x2y+xy2-y3)-(-0.5x3-x2y+0.3xy2).
73.-{2a2b-[3abc-(4ab2-a2b)]}.
74.(5a2b+3a2b2-ab2)-(-2ab2+3a2b2+a2b).
75.(x2-2y2-z2)-(-y2+3x2-z2)+(5x2-y2+2z2).
76.(3a6-a4+2a5-4a3-1)-(2-a+a3-a5-a4).
77.(4a-2b-c)-5a-[8b-2c-(a+b)].
78.(2m-3n)-(3m-2n)+(5n+m).
79.(3a2-4ab-5b2)-(2b2-5a2+2ab)-(-6ab).
80.xy-(2xy-3z)+(3xy-4z).
81.(-3x3+2x2-5x+1)-(5-6x-x2+x3).
83.3x-(2x-4y-6x)+3(-2z+2y).
84.(-x2+4+3x4-x3)-(x2+2x-x4-5).
85.若A=5a2-2ab+3b2,B=-2b2+3ab-a2,计算A+B.
86.已知A=3a2-5a-12,B=2a2+3a-4,求2(A-B).
87.2m-{-3n+[-4m-(3m-n)]}.
88.5m2n+(-2m2n)+2mn2-(+m2n).
89.4(x-y+z)-2(x+y-z)-3(-x-y-z).
90.2(x2-2xy+y2-3)+(-x2+y2)-(x2+2xy+y2).
92.2(a2-ab-b2)-3(4a-2b)+2(7a2-4ab+b2).
94.4x-2(x-3)-3[x-3(4-2x)+8].
(四)将下列各式先化简,再求值
97.已知a+b=2,a-b=-1,求3(a+b)2(a-b)2-5(a+b)2×(a-b)2的值.
98.已知A=a2+2b2-3c2,B=-b2-2c2+3a2,C=c2+2a2-3b2,求(A-B)+C.
99.求(3x2y-2xy2)-(xy2-2x2y),其中x=-1,y=2.
101.已知|x+1|+(y-2)2=0,求代数式5(2x-y)-3(x-4y)的值.
106.当P=a2+2ab+b2,Q=a2-2ab-b2时,求P-[Q-2P-(P-Q)].
107.求2x2-{-3x+5+[4x2-(3x2-x-1)]}的值,其中x=-3.
110.当x=-2,y=-1,z=3时,求5xyz-{2x2y-[3xyz-(4xy2-x2y)]}的值.
113.已知A=x3-5x2,B=x2-6x+3,求A-3(-2B).
(五)综合练习
115.去括号:{-[-(a+b)]}-{-[-(a-b)]}.
116.去括号:-[-(-x)-y]-[+(-y)-(+x)].
117.已知A=x3+6x-9,B=-x3-2x2+4x-6,计算2A-3B,并把结果放在前面带“-”号的括号内.
118.计算下式,并把结果放在前面带“-”号的括号内:
(-7y2)+(-4y)-(-y2)-(+5y)+(-8y2)+(+3y).
119.去括号、合并同类项,将结果按x的升幂排列,并把后三项放在带有“-”号的括号内:
120.不改变下式的值,将其中各括号前的符号都变成相反的符号:(x3+3x2)-(3x2y-7xy)+(2y3-3y2).
121.把多项式4x2y-2xy2+4xy+6-x2y2+x3-y2的三次项放在前面带有“-”号的括号内,二次项放在前面带有“+”号的括号内,四次项和常数项放在前面带有“-”号的括号内.
122.把下列多项式的括号去掉,合并同类项,并将其各项放在前面带有“-”号的括号内,再求2x-2[3x-(5x2-2x+1)]-4x2的值,其中x=-1.
123.合并同类项:
7x-1.3z-4.7-3.2x-y+2.1z+5-0.1y.
124.合并同类项:5m2n+5mn2-mn+3m2n-6mn2-8mn.
126.去括号,合并同类项:
(1)(m+1)-(-n+m);
(2)4m-[5m-(2m-1)].
127.化简:2x2-{-3x-[4x2-(3x2-x)+(x-x2)]}.
128.化简:-(7x-y-2z)-{[4x-(x-y-z)-3x+z]-x}.
129.计算:(+3a)+(-5a)+(-7a)+(-31a)-(+4a)-(-8a).
130.化简:a3-(a2-a)+(a2-a+1)-(1-a4+a3).
131.将x2-8x+2x3-13x2-2x-2x3+3先合并同类项,再求值,其中x=-4.
132.在括号内填上适当的项:[( )-9y+( )]+2y2+3y-4=11y2-( )+13.
133.在括号内填上适当的项:
(-x+y+z)(x+y-z)=[y-( )][y+( )].
134.在括号内填上适当的项:
(3x2+xy-7y2)-( )=y2-2xy-x2.
135.在括号内填上适当的项:
(1)x2-xy+y-1=x2-( );
(2)[( )+6x-7]-[4x2+( )-( )]=x2-2x+1.
136.计算4x2-3[x+4(1-x)-x2]-2(4x2-1)的值.
137.化简:
138.用竖式计算
(-x+5+2x4-6x3)-(3x4+2x2-3x3-7).
139.已知A=11x3+8x2-6x+2,B=7x3-x2+x+3,求2(3A-2B).
140.已知A=x3-5x2,B=x3-11x+6,C=4x-3,求
(1)A-B-C;
(2)(A-B-C)-(A-B+C).
141.已知A=3x2-4x3,B=x3-5x2+2,计算
(1)A+B;
(2)B-A.
142.已知x<-4,化简|-x|+|x+4|-|x-4|.
146.求两代数式-1.56a+3.2a3-0.47,2.27a3-0.02a2+4.03a+0.53的差与6-0.15a+3.24a2+5.07a3的和.
-0.3,y=-0.2.
150.已知(x-3)2+|y+1|+z2=0,求x2-2xy-5x2+12xz+3xy-z2-8xz-2x2的值.