Question

初一上册数学经典练习题 化简求值 急急急急急急、、

Answer 1

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=______．

Answer 2

34:51 48:60 125:375 22:143 32:128 63:210 125:30 70:413 90:495 15:450 49:28 0.25:0.45 1/4:1/8 2/3:1/7 4/15:4:25 3/7:4/21 5/9:1/6 8/3:4/3 4/9:2/3

Answer 3

题呢