答：因为：x>y>0因为：log3 (x-y/2)^2 =log3(xy)所以：(x-y/2)^2=xy>0所以：x^2-xy+(y^2)/4=xy所以：x^2-2xy+(y^2) /4=0所以：(x-y)^2=(3/4)y^2解得：x-y=(√3/2)y（负值不符合舍弃）所以：x/y=(2+√3) /2所以：log3...