80/(x+y) + 48/(x-y) =9 64/(x+y) + 96/(x-y) =12 怎样解,要过程,希望各大侠指点

{(x,y) |x|+|y| x>y?x:y (X+y )²-8(x+y)+48 x^/y-x-y^/y-x化简. 化简x(y-x)-y(x-y) 行列式计算 x y x+y y x+y x x+y x y|x y x+y ||y x+y x ||x+y x y | y/(x+y)-x/(x-y) x-y/x-x+y/y-(x+y)(x-y)/y² y/x=2 x y x+yy x+y xx+y x y (3x-y)(3y+x)-(x-y)(x+y) 化简x/y(x+y)-y/x(x+y) 化简 x / y(x+y) - y / x(x+y) = 化简:(x+ y)(x-y) +(x+ y) +(x-y) x+y (x+y) |x+y| x y x+yy x+y xx+y x y 化简y(x+y)+(x+y)(x-y)-x^2