已知,X>0,Y>0,求{3X^2+2*6^1/2*(XY+2YZ)}/X^2+Y^2+Z^2的最大值

已知x-3y=0,求(2x+y)/(x^2-2xy+y^2)X(x-y) 已知x+y=0,求x^3+x^2*y+xy^2+y^3 已知4x-2y=0,求x-y/3x+2y的值 已知(x+y)^(2)+(x+3y-4)^(2)=0,求x,y的平方和 已知x=2y,求2x-y分之x-3y的值.0 已知|2x-3y|+|3x-y-1|=0,求x,y的值. 已知2x²-xy-3y²=0,求x-y/x+y 已知|x+y|+(x-y+3)^2=0,求x,y的值 已知（x-y+3)²+根号2x+y＝0,求x+y的值. 已知x,y>0 2x+y+3=xy 求5x+4y最小值 已知x-3y=0,求（2x+y)/(x^2-2xy+y^2)*(x-y)的值已知x-3y=0,求（2x+y)/(x^2-2xy+y^2)*(x-y)的值 已知7x+5y/2y-x=3/2,且x≠0,求X/x-4y 已知x^2-3y^2=2xy(x>0,y>0),求代数式x+2y/x-y 已知x-3y=0,求(2x+y)/(x^2-2xy+y^2)*(x-y)的值. 已知x-3y=0,求2x+y/x-2xy+y乘(x-y)的值 已知y-2x=0,求3x²-2y²/(x+y)(x-y)的值 已知X,Y满足|X-Y-1|+（X+Y-3)^2=0求X,Y的值 已知:3x-5y=0,求x/y,x-y/y,x-y/x