(x/y) - (y/x) + (3/xy)
(x/y) - (y/x) + (3/xy) .. I assume you want to simplify this???.....assuming that the "y" in the last term is in the denominator, we have
[ x^2 - y^2 ] / xy + 3/(xy) =
[ x^2 - y^2 + 3 ] / (xy)