初一10道化简求值题

1．若a=-0.2,b=0.5,代数式-(|a2b|-|ab2|)的值为______．
2．一个多项式减去3m4-m3-2m+5得-2m4-3m3-2m2-1,那么这个多项式等于______．
3．-(2x2-y2)-[2y2-(x2+2xy)]=______．
4．若-3a3b2与5ax-1by+2是同类项,则x=______,y=______．
5．(-y+6+3y4-y3)-(2y2-3y3+y4-7)＝______．
6．化简代数式4x2-[7x2-5x-3(1-2x+x2)]的结果是______．
7．2a-b2+c-d3=2a+( )-d3=2a-d3-( )=c-( )．
8．3a-(2a-3b)+3(a-2b)-b=______．
9．化简代数式x-[y-2x-(x+y)]等于______．
10．[5a2+( )a-7]+[( )a2-4a+( )]=a2+2a+1．