x²－6y²=﹣xy 且x＞0,y＞0 求分式x+3y／x－y的值

x²－6y²=﹣xy 且x＞0,y＞0 求分式x+3y／x－y的值
x²－6y²=﹣xy 且x＞0,y＞0 求分式x+3y／x－y的值

x²－6y²=﹣xy 且x＞0,y＞0 求分式x+3y／x－y的值
(x+3y)(x-2y)=0
x=-3y (舍去） x=2y
∴(x+3y)/(x-y)
=5y/(2y-y)
=5