正数X,Y满足x2-y2=2xy,求（x-y)除以（x+y)的值

正数X,Y满足x2-y2=2xy,求（x-y)除以（x+y)的值
正数X,Y满足x2-y2=2xy,求（x-y)除以（x+y)的值

正数X,Y满足x2-y2=2xy,求（x-y)除以（x+y)的值
x2-2xy+Y2－2*y2=0
(X-Y)²-2Y²=0
X=(1-根号2）因为为正数,所以不合题意,舍去
X=(1+根号2）Y
(x-y)/(X+Y)=根号2-1