{2x+y/3-2y=0 2(2x+y)-5=7y

x-y/x-x+y/y-(x+y)(x-y)/y² y/x=2 (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) (x+y)(2x-3y)=? 7y(x-3y)-2(3y-x)=0 .x=?,y=? 【2(x-y)^3-8(x-y)^2(x+y)+6y(x-y)^2】/2(x-y)^2= 已知x-y=3,求[（x+y)(x-y)-(x-y)^2+2y(x-y)]除以的值 已知3x =2y 求x/x+y+y/x-y-y²/x²-y² x(x-y)2-(y-x)3 y+y'-2y=2x 微分方程y - 2y' + y = x 化简y(x+y)+(x+y)(x-y)-x^2 (X,Y) f(x,y)={12y^2,0 计算：y(x-y)^2+(y-x)^3=? y'=(2x+y)/(3x-y)微分方程通解 12y(x-y)^2-8(x-y)^3=? 计算：x+2y/x-y+2x/y-x-3y/x-y