(x-y)/(2x+2y)与(xy)/（x+y）²通分要过程

2xy/(x+y)^与x/x^-y^ 2xy/(x+y)(x+y)与x/(x+y)(x-y)怎么通分 (-x-y)(x^2+xy+y^2) 化简x^-y^/x^-2xy+y^ 2*(x-y)²(y-x)(xy) （x^2+xy/x-y)/（xy/x-y)计算 已知x-xy =21,xy-y=-12,分别求式子x-y与x-2xy +y x³-xy²/x³+2x²y+xy² 与x²-y²/x(x+3y)+y(y-x) 急、、、、 X-Y/2X+2Y XY/X+Y² 因式分解：x×x-xy-2y×y-x-y 设x,y∈R,比较(x*2+y*2)*2与xy(x+y)*2 通分x-y/2x+2y与xy/(x+y）的2次方 通分x-y/2x+2y与xy/(x+y)2 通分 2X+2Y分之X-Y与(X+Y)²分之XY 通分 x-y/2x+2y 与 xy/(x+y)² 的 (x-y)/(2x+2y)与(xy)/（x+y）²通分要过程 2x+2y/x-y与(x+y)²/xy 怎么通分 2x+2y/x-y与（x²+y²）/xy通分