设根号x(根号x-根号Y)=根号xY+3Y,求2x+3根号xY/3X-Y的值
问题描述:
设根号x(根号x-根号Y)=根号xY+3Y,求2x+3根号xY/3X-Y的值
答
由√x(√x-√y)=√xy+3y,得x-2√xy-3y=0,(√x-3√y)(√x+√y)=0,上式要成立,就只能:(√x-3√y)=0或(√x+√y)=0,解得x=9y(x>0时)或x=y=0.你的这个"求2x+3根号xY/3X-Y的值"中间部份"3根号xY/3X)"不是很明确,是"3√(xY/...