1、3ab-4ab+8ab-7ab+ab=______． a=3,b=2
2．7x-(5x-5y)-y=______． x=2,y=3
3．23a3bc2-15ab2c+8abc-24a3bc2-8abc=______． a=2,b=1,c=3
4．-7x2+6x+13x2-4x-5x2=______． x=2
5．2y+(-2y+5)-(3y+2)＝______． y=-1
6．(2x2-3xy+4y2)+(x2+2xy-3y2)=______． x=-2,y=0
7．2a-(3a-2b+2)+(3a-4b-1)=______．a=-2,b=2
8．-6x2-7x2+15x2-2x2＝______． x=3
9．2x-(x+3y)-(-x-y)-(x-y)＝______． x=y=2
10．2x+2y-[3x-2(x-y)]=______． x=2,y=2
11．5-(1-x)-1-(x-1)=______． x=-2
12．( )+(4xy+7x2-y2)=10x2-xy． x=-2,y=-1
13．(4xy2-2x2y)-( )=x3-2x2y+4xy2+y3． x=-2,y=0
14．已知A=x3-2x2+x-4,B=2x3-5x+3,计算A+B=______．
15．已知A=x3-2x2+x-4,B=2x3-5x+3,计算A-B=______．
16．若a=-0.2,b=0.5,代数式-(|a2b|-|ab2|)的值为______．
17．一个多项式减去3m4-m3-2m+5得-2m4-3m3-2m2-1,那么这个多项式等于______．
18．-(2x2-y2)-[2y2-(x2+2xy)]=______．
19．若-3a3b2与5ax-1by+2是同类项,则x=______,y=______．
20．(-y+6+3y4-y3)-(2y2-3y3+y4-7)＝______．
21．化简代数式4x2-[7x2-5x-3(1-2x+x2)]的结果是______．
22．2a-b2+c-d3=2a+( )-d3=2a-d3-( )=c-( )．
23．3a-(2a-3b)+3(a-2b)-b=______．
24．化简代数式x-[y-2x-(x+y)]等于______．
25．[5a2+( )a-7]+[( )a2-4a+( )]=a2+2a+1．
26．3x-[y-(2x+y)]=______．
27．化简|1-x+y|-|x-y|(其中x＜0,y＞0)等于______．
28．已知x≤y,x+y-|x-y|=______．
29．已知x＜0,y＜0,化简|x+y|-|5-x-y|=______．
30．4a2n-an-(3an-2a2n)＝______．
31．若一个多项式加上-3x2y+2x2-3xy-4得
2x2y+3xy2-x2+2xy,
则这个多项式为______．
32．-5xm-xm-(-7xm)+(-3xm)=______．
33．当a=-1,b=-2时,
[a-(b-c)]-[-b-(-c-a)]＝______．
34．当a=-1,b=1,c=-1时,
-[b-2(-5a)]-(-3b+5c)＝______．
35．-2(3x+z)-(-6x)+(-5y+3z)=______．
36．-5an-an+1-(-7an+1)+(-3an)＝______．
37．3a-(2a-4b-6c)+3(-2c+2b)=______．
38．9a2+[7a2-2a-(-a2+3a)]=______．
39．当2y-x=5时,5(x-2y)2-3(-x+2y)-100=______
41、(3ab-2a)÷a =a(3b-2)/a=3b-2
42、（x^3-2x^y)÷(-x^2)= x-2y
43、-21a^2b^3÷7a^2b =-3b^2
44、(6a^3b-9a^c)÷3a^2 =3a^2(2ab-3c)/3a^2=2ab-3c
45、(5ax^2+15x)÷5x=5x(a+3x)÷5x =a+3x
46、(a+2b)(a-2b)=a^2-4b^2
47、(3a+b)^2=9a^2+b^2 +12ab
48、(1/2 a-1/3 b)^2 =1/4a^2+1/9b^2-1/18ab
49、(x+5y)(x-7y)=x^2-7x+5x-35y^2=x^2-2x-35y^2
50、(2a+3b)(2a+3b)4a^2+9b^2 ++12ab
51、(x+5)(x-7)=x^2-7x+5x-35=x^2-2x-35
52、5x^3×8x^2 =40x^5
53、-3x×(2x^2-x+4)=-6x^3+3x^2-12x
54、11x^12×(-12x^11)=-132 x^23
55、(x+5)(x+6)=x^2+11x+30
56、(2x+1)(2x+3)=4x^2+6x+2x+4=4x^2+8x+4
57、3x^3y×(2x^2y-3xy)=6x^5y^2-9x4y^2
58、2x×(3x^2-xy+y^2)=6x^3-2x^2y+2xy^2
59、(a^3)^3÷(a^4)^2=a^9/a^8=a
60、(x^2y)^5÷(x^2y)^3 =x^2y)^2
61、(y^3)^3÷y^3÷(-y^2)^2 =y^6÷(-y^2)^2=y^6/y^4=y^2
62、(-2mn^3)^3=-8m^3n^9
63、(2x-1)(3x+2)=6x^2+x-2
64、(2/3 x+3/4y)^2=4/9x^2+xy+9/16y^2
65、2001^2-2002×2002=(2001+2002)(2001-2002)=-4003
66、(2x+5)^2-(2x-5)^2=（2x+5+2x-5）（2x+5-2x+5）=4x*10=40x
67、-12m^3n^3÷4m^2n^3=-3m
68、2x^2y^2-4y^3z=2y^2*(x^2-2yz)
69、1-4x^2=（1-2x）（1+2x）
70、x^3-25x=x(x^2-25)
71、x^3+4x^2+4x=x(x+2)^2
72、(x+2)(x+6)=x^2+8x+12
73、2a×3a^2=6a^3
74、(-2mn^2)^3=-8m^3*n^6
75、（-m+n)(m-n）=-m^2+2mn-n^2
76、27x^8÷3x^4=9x^4
77、(-2x^2)×(-y)+3xy×(1-1/3 x)=2x^2*y+3xy-x^2*y=x^2*y+3xy
78、am-an+ap=a(m-n+p)
79、25x^2+20xy+4y^2=(5x+2y)^2
80、(-4m^4+20m^3n-m^2n^2)÷(-4m^2)=m^2-5mn-1/4n^2
81、(12p^3q^4+20p^3q^2r-6p^4q^3)÷(-2pq)^2=3pq^2+5pr-3/2p^2*q
82、[4y(2x-y)-2x(2x-y)]÷(2x-y)=4y-2x
83、(x^2y^3-1/2 x^3y^2+2x^2y^2)÷1/2 xy^2=2xy-x^2+4x
84、(4a^3b^3-6a^2b^3c-2ab^5)÷(-2ab^2)=-2a^2*b+3abc+b^3
85、（ax+bx)÷x=a+b
86、(ma+mb+mc)÷m=a+b+c
87、(9x^4-15x^2+6x)÷3x=3x^3-5x+2
88、(28a^3b^2c+a^2b^3-14a^2b^2)÷(-7a^2b)=-4abc-1/7b^2+2b
89、(6xy^2)^2÷3xy=12xy ^3
90、24a^3b^2÷3ab^2=8a^2
