関連ワード:  is 8 9 a rational number    is 9 8 a rational number between 1 and 2    is negative 8 9 a rational number    is 8 9 a rational or irrational number    8 9 is a rational number or not    is 9 7 8 a rational number    is 7 1 9 a rational number between 7 and 8    is 9 a rational number    is 11/9 a rational number