（x+y）(x-1)-xy-y^2 怎么因式分解?

（x+y）(x-1)-xy-y^2 怎么因式分解? 1/(1+y²/x²)×（y'x-y）/x²怎么化简成xy'-y我画出来是(xy'-y)/x^2+y^2 对于(y一撇）y`=y/x(y-1)求导,我求的结果是y``=-y^2-y`x+y/x^2(y-1)^2 怎么不对啊,我的求导过程是：y`x(y-1) - [x(y-1)]` y y`xy-y`x-(y-1+xy`)y -y^2-y`x+yy``=-------------------------=----------------------=-----------------x^2 (y-1 (x^2-xy)y÷y-x/xy怎么做? （x/x+y+2y/x+y）乘以xy/x+2y除以（1/x+1/y） 用分式加减2怎么做 1.（xy-1）^2-(x+y-2xy)(2-x-y)2.(x+y)(x+y+2xy)+(xy-1)(xy+1) 2xy/(x+y)(x+y)与x/(x+y)(x-y)怎么通分 x²-y²+5x+3y+4（x+y-2xy)(x+y-z)+(xy-1）² .(x+y-2)(x+y-2xy)+(xy-1)^2 分解因式：(X+Y）*（X+Y+2XY）+（XY+1）*（XY-1） (xy+1)^2+(x+y)(x+y-2xy-2)怎么解啊是因式分解 x+y-1=xy/（x+y-xy）怎么因式分解 (x²-4y²)÷(2x+y)/xy×1/x(2y-x）(2x+y)/xy 1/x(2y-x） 都是一项 (x+y)(x+y+2xy)+(xy+1)(xy-1)(x+y)(x-y)+4(y-1) X^2-2XY+Y^2-X+Y-2=0怎么算等于(x-y-2)(x-y+1)? (1/y-1/x)乘（xy）/（x^2-2xy+y^2）怎么化简 x根号x+x根号y/xy-y^2)-（x+根号xy+y/x根号x-y根号）y xy-1+x-y