化简下面的题：（2x+y)+(4x+1/1*2y)+(6x+1/2*3y)+(8x+1/3*4y)+…+(18+1/8*

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 {3(x+y)-4(x-y)=4 {x+y/2 + x-y/6=1 化简下面的题：（2x+y)+(4x+1/1*2y)+(6x+1/2*3y)+(8x+1/3*4y)+…+(18+1/8* 9y=3x-(x-1),4(x+y)-(2x+4)=8y 化简求值:(x+y)-(2x+1/2y)-(3x+1/6y)-(4x+1/12y)-(5x+1/20y)-.(10x+1 （x+2)(x+3) (x-4)(x+1) (y+4)(y-2) (y-5)(y-3) 化简代数式的几道题3(x-1)-(x-5)2(x^2-y^2)-3(x^2-2y^2)(x+y)+3(x-y)-4(x+ 因式分解 (1)6(x-y)^3-3y(y-x)^2 (2)x(x-y)(a-b)-y(y-x)( 求解;一 (x-8y)(x-y) 二 (Y+2)(Y-2)-(Y-1)(Y+5) 三 (3X+4)(3X-4)-(2X+ 先化简再求值(x-y)(x+y)-(x-2y) 的完全平方+x(3x-5y)-(x-y)(x-2y),其中x=1/2 y 若x=-1/4,能否确定代数式(2x-y)(2x+y)+(2x-y)(y-4x)+2y(y-3x)的值? 1、x(x-y)(x+y)-x(x+y)^2