化简8x-4x-3+2y

计算(x^8-x^7y+x^5y^3-x^4y^4+x^3y^5-x^y^7+y^8)(x^2+xy+y^2) x^8-x^7y+x^6y^2-x^5y^3+x^4y^4-x^3y^5+x^2y^-xy^7+y^8 1.（（y+2x)(-2x+y)+4(x+2y)^2)/3y 2.（2(x-y)^3-8(x-y）^2(x+y)+6y( 化简(x+y)+(2x+1/2y)+(3x+2/3y)+(4x+3/4y)+...+(9x+8/9y)=? 化简:(x-3y)(x+y)-(x-2y)(x+2y)-(x-y)平方 化简[(3x+4y)^2-(2x+y)(2x-y)+(-x+y)(5x-y)]除以-2y,其中x=-1,y=1 计算:1/(x-y)-1/(x+y)-2y/(x^2+y^2)-4y^3/(x^4+y^4)-8x^7/(x^8+y^8 9y=3x-(x-1),4(x+y)-(2x+4)=8y 化简：（2x-y)²-4(x-y)(x+y) x/x-y*y^2/x+y-x^3y2/x^4-y^4/x^2/x^2+y^2 化简(2x^3y^3+x^4y^2+x^2y^4)^2-x^2y^2(x+y)^2,x=2012,y=-2011 化简(x+y)-(2x+y/2)-(3x+y/6)-(4x+y/12)-(5x+y/20)-……-(10x+y/90)