初一口算100题.docx
初一口算100题1.3ab-4ab+8ab-7ab+ab=.2.7x-(5x-5y)-y=3.23a3bc2-15ab2c+8abc-24a3bc2-8abc=.4.-7x2+6x+13x2-4x-5x2=.5. 2y+(-2y+5)-(3y+2)=.6. (2x2-3xy+4y2)+(x2+2xy-3y2)三.7. 2a-(3a-2b+2)+(3a-4b-l)=.13. -6x2-7x2+15x2-2x2=.14. 2×-(x+3y)-(-x-y)-(x-y)=.16. 2x+2y-3x-2(×-y)=.17. 5-(l-x)-l-(x-l)三.18. ()+(4xy+7×2-y2)=10×2-×y.19. (4xy2-2x2y)-()=x3-2x2y+4xy2+y3.21 .已知A=x3-2x2+x-4,B=2x3-5x+3,计算A+B=.22 .己知A=x3-2x2+x4,B=2×3-5×+3,计算A-B=.23 .若a=-0.2,b=0.5,代数式-(恰2吐故2|)的值为.25. 一个多项式减去3m4-m3-2m+5得-2m4-3m3-2m2-l,那么这个多项式等于26. -(2×2-y2)-2y2-(x2+2xy)=.27. 若-3a3b2与5ax-lby+2是同类项，则X=，y=.28. (-y+6+3y4-y3)-(2y2-3y3+y4-7)=.29. 化简代数式4x2-7x25x3(l2x+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xy2x(x+y)等于.33. 5a2+()a-7+()a2-4a+()=a2+2a+l.34. 3x-y-(2x+y)三.35. 化简+yHy(其中xv。，y>0)等于36. 己知×y,x+y-x-yI=.37. 已知×<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+3xy2x2+2xy,则这个多项式为.40 .-5xm-xm-(-7xm)+(-3xm)=.41 .当a=-l,b=2时，a-(b-c)-b-(-c-a)=_43. 当a=-l»b=l>c=-l时，-b-2(-5a)-(-3b+5c)=.44. -2(3x+z)-(-6x)+(-5y+3z)=.45. -5an-an+l-(-7an+l)+(-3an)=46. 3a-(2a-4b-6c)+3(-2c+2b)三.48.9a2+7a2-2a-(-a2+3a)三50.当2y-x=5时，5(×-2y)2-3(-×+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的是口A. 3x-(5x2+6×3-10×);B. 3x-(5x2+6x3+10x);C. 3x-(5x2-6x3+10x)：D. 3x-(5x2-6x3-10x).53.把(Hy)+3(x+y卜5(x+y)合并同类项得口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)等于口A. -7a+10b;B. 5a+4b;C. -a-4b；D.9a-10b.S减去3m等于5m2-3m-5的代数式是口A. 5(m2-l);B. 5m2-6m-5;C. 5(m2+l);D. -(5m2+6m-5).S将多项式2ab-9a2-5ab-4a2中的同类项分别结合在一起，应为口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=l时,-a2b+3ba2-(-2a2b)等于口A. 20；B. 24；C. 0；D. 16.中，正确的选择是UA.没有同类项；B.(2)与是同类项；C(2)与是同类项;D.与不是同类项.59.若A和B均为五次多项式，则A-B一定是口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.-(×+y)+-(+y)等于口A.0；B. -2y；C. x+y；D. -2x-2y.61.若A=3x2-5x+2,B=3x2-5×+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=-l时，-2m2-卜4m2+(-m2)等于口A. -7；B. 3；C. 1；D. 2.63.当m=2,n=l时，多项式-m-(2m-3n)+-(-3m卜4nJ等于口A.1；C. 3；D. 5.65. -5an-an-(-7an)+(-3an)等于口A. -16an；B. -16；C. -2an；D. -2.66. (5a-3b)-3(a2-2b)等于口A. 3a2+5a+3b;B.2a2+3b;C. 2a3-b2;D. -3a2+5a-5b.67. x3-5x2-4x+9等于口A. (x3-5x2)-(-4x+9);B. x3-5x2-(4x+9);C. -(-×3+5×2)-(4x-9);D. x3+9-5x2-4×).69. 4x2y-5xy2的结果应为口A. -x2y；B. -1；C. -×2y2;D.以上答案都不对.(三)化简70. (4x2-8x+5)-(x3+3x2-6×+2).72.(0.3×3-x2y+xy2-y3)-(-0.5x3-x2y+0.3xy2).73.-2a2b-3abc-(4ab2-a2b).74.(5a2b+3a2b2-ab2)-(-2ab2+3a2b2+a2b).75.(×2-2y2-z2)-(-y2+3x2-z2)+(5×2-y2+2z2).76. (3a6-a4+2a5-4a3-l)-(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+l)-(5-6x-x2+x3).83. 3x-(2x-4y-6x)+3(-2z+2y).84. (-×2+4+3×4-x3)-(x2+2×-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)-3x-3(4-2x)+8.(四)将下列各式先化简，再求值97.已知a+b=2,a-b=-l,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=-l,y=2.101.已知x+l+(y-2)2=0,求代数式5(2xy)3(x4y)的值.
