(12-2x)/X=(-16-2Y)/Y X^2+Y^2=25 Y

x-y/x-x+y/y-(x+y)(x-y)/y² y/x=2 (12-2x)/X=(-16-2Y)/Y X^2+Y^2=25 Y (X,Y) f(x,y)={12y^2,0 12y(x-y)^2-8(x-y)^3=? 3x+y=2 -y/x+y=123x+y=2 （-y/x）+y=12 8（x-y)=3（x+y)-12 6（x+y)=4（2x-y)+16 8（x-y)=3（x+y)-12 6（x+y)=4（2x-y)+16 填空：x-y/x+y=( )/x^2-y^2 （x-y)2•(y-x)³(x-y)=? y+y'-2y=2x 微分方程y - 2y' + y = x (x-y) (x-2y)+(x+2y) (x-3y)-2(x-3y) (x-4y)= (x+y)(x-y)+(x-y)平方-(x-y)(3x-y) 其中x=-2 y=3分之一 已知x-y/x+y=3,求代数式5(x-y)/x+y-x+y/2(x-y) 化简y(x+y)+(x+y)(x-y)-x^2 (x+y)^2-16(x-y)^2 (x+y)^2-16(x-y)^2 16-8（x-y)+(x-y)2