x/y=3/2 求x-y/x+y的值

已知x-y=3,求[（x+y)(x-y)-(x-y)^2+2y(x-y)]除以的值 若2/x-1/y=3,求[y/x-y/x-y(x-y/x-x+y)]/x-2y/x的值 y=3(x-y),x=2(x-y)求x,y的值 已知x-y=1,求[(x+2y)^2+(2x+y)(x-4y)-3(x+y)(x-y)]除以y的值大神们帮帮忙 已知x-y=1,求[(x+2y)²+(2x+y)(x-4y)-3(x+y)(x-y)]÷y的值 已知(x+2y)(2x-3y)=y(y-4x),试求x/y的值 已知x+y=a,2x-y=-2a,求[（x/y-y/x)/(x+y)-x(1/x-1/y)]/[(x+1)/y]的值 已知x≠y,x^2-x=y^2-y,求x+y的值. 已知|3x-y|+|x+y|=0,求x-y除以x*y的值. x,y 满足x(x-2)-y(y-6)=-10,求x,y的值 正数x,y满足x-y=2xy,求x-y/x+y的值. 已知2x-y/x+2y=3,求2(2x-y)/x+2y-9(x+2y)/2x-y+3的值. 已知（x+y）2 =2,(x-y)3 =3,求(x+y)7(x-y)2(x+y)3(y-x)4 的值 已知x+y分之x-y=2,求2x+2y分之x-y-3x-3y分之2x+2y的值 已知x+y分之x-y=2,求2x+2y分之x-y-3x-3y分之2x+2y的值 已知2x-y/x+3y=2,求代数式4x-2y/x+3y减4x+12y/2x-y的值 已知2x-y/x+3y=2,求代数式4x-2y/x+3y减4x+12y/2x-y的值 当2x-y/x+y=3时,求代数式2x-y/2x+2y+x+y/6x-3y的值.