x-y/x-x+y/y-(x+y)(x-y)/y² y/x=2

来源：学生作业帮编辑：神马作文网作业帮分类：数学作业时间：2024/11/06 21:33:33

以上错误,修改如下：
y/x=2→y=2x
(x-y)/x-(x+y)/y-(x+y)(x-y)/y^2
=((xy-y^2)-(x^2+xy))/xy-(x^2-y^2)/y^2
=-(x^2+y^2)/xy--(x^2-y^2)/y^2
把y=2x代入以上方程得：
=-(x^2+4x^2)/2x^2-(x^2-4x^2)/4x^2
=-5x^2/2x^2+3x^2/4
-5/2+3/4
=-7/4

{(x,y) |x|+|y| x>y?x:y 1、x(x-y)(x+y)-x(x+y)^2 [x(x-y)-y(x-y)+(x+y)(x-y)]÷2x其中x=2012 y=2013 (2x-y)²-4(x-y)(x+2y) 化简：（2x-y)²-4(x-y)(x+y) (x+y) X、Y 1.(x-y)(x+y)+(x-y)+(x+y) |x|+|y| x y x+yy x+y xx+y x y 因式分解:x²(x-y)+(y-x)