Vì: 997/998 = 1994 / 1996
Ta có :
(1995 / 1995) - (2 / 1995) = 1993/1995
(1996 / 1996) - (2 / 1996) = 1994 / 1996
Vì: 1995 / 1995 = 1996 / 1996 (= 1)
Mà: 2 / 1995 > 2 / 1996
==> (1995 / 1995) - (2 / 1995) < (1996 / 1996) - (2 / 1996)
==> 1993/1995 < 1994 / 1996
==> 1993/1995 < 997/998 .