化简(x+y)+(2x+1/2y)+(3x+2/3y)+(4x+3/4y)+...+(9x+8/9y)=?

化简：{2/3x-2/(x+y)[(x+y)/3x-x-y]}/(x+y)/x 化简3x-2/(x+y)[(x+y)/3x-x-y]÷(x-y)/x 化简:(x-3y)(x+y)-(x-2y)(x+2y)-(x-y)平方 化简y(x+y)+(x+y)(x-y)-x^2 化简:5(x-y)+2(x+y)-3(x-y) 化简3(x-y)-7(x--y)+2(y-x) 化简[(3x+4y)^2-(2x+y)(2x-y)+(-x+y)(5x-y)]除以-2y,其中x=-1,y=1 1/(x-y)+1/(x+y)+2x/(x^2+y^2)+4x^3/(x^4+y^4)化简 (x+y)-(x-y)^3÷(x-y)(x+y)×2y化简e , 化简(X-2Y)-(Y-3X) 化简 3x(x^2-x-1)-(x+1)(3x^-x) X^3(x-y)+x(y-x) x²/xy-x/y 3x/4x+y - x-2y/4x+y (1-y/y+x)÷x/y²-x² 化简,求值：[(x/y)-(y/x)]除以[(x/y)+(y/x)-2]除以[1+(y/x)],其中x=1/2,y=1/3 若2/x-1/y=3,求[y/x-y/x-y(x-y/x-x+y)]/x-2y/x的值 x(x-y)2-(y-x)3 (2x+3y)(3x-2y)-(x-2y)(x+2y)化简 化简 [(x-y)^2(x+y)^-2/2(x+y)^2(x-y)^-2]^-3 化简(x-3y)(3x+y)-(2x-3y)(2x-3y)