(382+498×381) = (1+499×381)/(381×498-116+498)
___________________ = (1+499×381)/(381×498+382)
(382×498-116) == (1+499×381)/(381×499+1) =1
(382+498×381) = (1+499×381)/(381×498-116+498)
___________________ = (1+499×381)/(381×498+382)
(382×498-116) == (1+499×381)/(381×499+1) =1