y(x+y)-(2x+y)(x-y)-x的2次方,其中x=-2,y=2分之1(先化简,再求值）先化简，再求值

x-y/x-x+y/y-(x+y)(x-y)/y² y/x=2 {(x,y) |x|+|y| x>y?x:y 化简y(x+y)+(x+y)(x-y)-x^2 (x+y)(x-y)-(x-y)^2如题 (x+y)(x-y)-(x-y)^2 【2(x-y)(x-y)(x-y)-8(x-y)(x-y)(x+y)+6y(x-y)(x-y)]/2(x-y)(x-y) 因式分解x(x+y)(x-y)-x(x+y)^2 [(x-y)^2-(x+2y)(x-2y)]/y 计算:y-x分之x+y+x-y分之y-y-x分之2x-y x^2(x-y)+(y-x) x(x-y)2-(y-x)3 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)^2+(x+y)(x-y)】除以 2x [(x-y)²+(x+y)(x-y)]除以2x [2/3x-2/x+y(x+y/3x-x-y)]/x-y/x