已知x/2=y/3,你能用两种方法计算x^2-y^2/x^2-2xy-3y^2的值吗?

已知x/2=y/3,你能用两种方法计算x^2-y^2/x^2-2xy-3y^2的值吗?
x/2=y/3
x=2y/3
y=3x/2
(x²-y²)/(x²-2xy-3y²)
=(x-y)(x+y)/(x-3y)(x+y)
=(x-y)/(x-3y)
当x=2y/3时
=(2y/3-y)/(2y/3-3y)
=-1/3y/(-7/3y)
=1/7
当y=3x/2时
（x-y)/(x-3y)
=(x-3x/2)/(x-3*3x/2)
=-1/2x/(-7/2x)
=1/7