题目内容：

数学50道解方程(不要应用题那种),合并同类项

优质解答

3ab-4ab+8ab-7ab+ab
23a3bc2-15ab2c+8abc-24a3bc2-8abc
2y+(-2y+5)-(3y+2)
(2x2-3xy+4y2)+(x2+2xy-3y2)
2a-(3a-2b+2)+(3a-4b-1)
2x-(x+3y)-(-x-y)-(x-y)
2x+2y-[3x-2(x-y)]
5-(1-x)-1-(x-1)
(4xy2-2x2y)-( )=x3-2x2y+4xy2+y3．
3x-2x2+x-4+2x3-5x+3
3x-2x+x-4-(2x3-5x+3)
-(2x2-y2)-[2y2-(x2+2xy)]
(-y+6+3y4-y3)-(2y2-3y3+y4-7)
4x2-[7x2-5x-3(1-2x+x2)]
3a-(2a-3b)+3(a-2b)-b
x-[y-2x-(x+y)]
3x-[y-(2x+y)]
4a2n-an-(3an-2a2n)
2x2y+3xy2-x2+2xy-(3x2y+2x2-3xy-4)
-5xm-xm-(-7xm)+(-3xm)
[a-(b-c)]-[-b-(-c-a)] 当a=-1,b=-2时
b-2(-5a)]-(-3b+5c)
-2(3x+z)-(-6x)+(-5y+3z)
-5an-an+1-(-7an+1)+(-3an)
3a-(2a-4b-6c)+3(-2c+2b)
9a2+[7a2-2a-(-a2+3a)]
3ab-4ab+8ab-7ab+ab=______.
7x-(5x-5y)-y=______.
23a3bc2-15ab2c+8abc-24a3bc2-8abc=______.
-7x2+6x+13x2-4x-5x2=______.
2y+(-2y+5)-(3y+2)=______.
(2x2-3xy+4y2)+(x2+2xy-3y2)=______.
2a-(3a-2b+2)+(3a-4b-1)=______.
-6x2-7x2+15x2-2x2=______.
2x-(x+3y)-(-x-y)-(x-y)=______.
2x+2y-[3x-2(x-y)]=______.
5-(1-x)-1-(x-1)=______.
( )+(4xy+7x2-y2)=10x2-xy.
(4xy2-2x2y)-( )=x3-2x2y+4xy2+y3.
已知A=x3-2x2+x-4,B=2x3-5x+3,计算A+B=______.
已知A=x3-2x2+x-4,B=2x3-5x+3,计算A-B=______.
若a=-0.2,b=0.5,代数式-(|a2b|-|ab2|)的值为______.
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______.
-(2x2-y2)-[2y2-(x2+2xy)]=______.
若-3a3b2与5ax-1by+2是同类项,则x=______,y=______.
(-y+6+3y4-y3)-(2y2-3y3+y4-7)=______.
化简代数式4x2-[7x2-5x-3(1-2x+x2)]的结果是______.
2a-b2+c-d3=2a+( )-d3=2a-d3-( )=c-( ).
3a-(2a-3b)+3(a-2b)-b=______.
化简代数式x-[y-2x-(x+y)]等于______.
[5a2+( )a-7]+[( )a2-4a+( )]=a2+2a+1.
3x-[y-(2x+y)]=______.
化简|1-x+y|-|x-y|(其中x0)等于______.
已知x≤y,x+y-|x-y|=______.
已知x