关于初一上册去括号,合并同类项数学题(计算题)

5个回答

  • 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.