谁能帮我出20道去括号,合并同类项的数学题

出20道去括号,合并同类项的数学题(至少两个括号)... 出20道去括号,合并同类项的数学题(至少两个括号) 展开
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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.
黄佳伟123
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1 6(x^3-x^2+3x)+4(2x^2+x)+x^3-5

2 5x-4c+(3c-2b+5a)+5x-(3c-2b+7x)

3 4(x+y)-x+4y-9(x+2y)-3y-4(3y-2x)

4 (+3a)+(-5a)+(-7a)+(-31a)-(+4a)-(-8a)

5 (-7y2)+(-4y)-(-y2)-(+5y)+(-8y2)+(+3y)

6 (3x2y-2xy2)-(xy2-2x2y)

7 (4x2-8x+5)-(x3+3x2-6x+2)

8 (0.3x3-x2y+xy2-y3)-(-0.5x3-x2y+0.3xy2)

9 -{2a2b-[3abc-(4ab2-a2b)]}

10 (x2-2y2-z2)-(-y2+3x2-z2)+(5x2-y2+2z2)

11 (3a6-a4+2a5-4a3-1)-(2-a+a3-a5-a4)

12 (4a-2b-c)-5a-[8b-2c-(a+b)]

13 (2m-3n)-(3m-2n)+(5n+m)

14 (3a2-4ab-5b2)-(2b2-5a2+2ab)-(-6ab)

15 xy-(2xy-3z)+(3xy-4z)

16 (-3x3+2x2-5x+1)-(5-6x-x2+x3)

17 3x-(2x-4y-6x)+3(-2z+2y)

18 (-x2+4+3x4-x3)-(x2+2x-x4-5)

19 7x-5a-(7c+3a-7b)-[-(-5x-7c+3b+9a)]

20 7b-5a+4c-(4a+7b-3c+3b)+2b-3(-5a+7b-11b)-33b
你说的20道,我没多也没少只是出题没有其他成分。。最佳给我吧
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1.x-3(1-2x+x²)+2(-2+3x-x²) 2.-5(x-y)²+6(x-y)²+2(y-x)²
3.5(2a-b)-2(6a-2b+4)+(4a-3b-2) 4.5abc-{2a²-[3abc-(4ab²-2a²b)]}
5.(2x²+ax-y+6)-(2bx²-3x+5y-1) 6.(x³-2x²+x-4)-(2x³-5x-4)
7.3(5m-6n)+2(3m-4n) 8.-(5a+b)-[4a²-(2b-a²)-1]
9.5(a²b-2ab²+c)-4(2c+4a²b-2ab²) 10.(2x³-xyz)-2(x³-y³+xyz)+(xyz-2y³)
11.(-x+2x²+5)+(4x²-3-6x) 12.(3a²-ab+7)-(-4a²+2ab+7)
13.-x+(2x-2)-(3x+5) 14.3a²+a²-(2a²-2a)+(3a-a²)
15.5(3a²b-ab²)-(ab²+3a²b) 16.(-x²+5+4x)+(5x-4+2x²)
17.(5a+4c+7b)+(5c-3b-6a) 18.(8xy-x²+y²)-(x²-y²+8xy)
19.3x²-[7x-(4x-3)-2x²] 20.(4a²b-3ab)+(-5a²b+2ab)
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1.4(x+y)=x+4y-9(x+2y)
多的就不出了 题做多了不一定是好事情 会做掌握到方法就成.
去括号合并同类项基本步骤就是先去掉括号 移项 在合并. 在去括号 移项之前请注意+ -号的变换.
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