1/2 7/9 13/16 19/13 5/6 ( )A．10/11 B．11/12 c．31/37 D．33/37
熱心網友
我猜測題有印刷錯誤,應是:1/2 7/9 13/16 19/23 5/6 ( )A．10/11 B．11/12 c．31/37 D．33/37 答案是31/37.理由:1/2 ,7/9 ,13/16 ,19/23 ,25/30 ,31/37,.....An=(6n-5)/(7n-5)分子和分母各為一等差數列,
1/2 7/9 13/16 19/13 5/6 ( )A．10/11 B．11/12 c．31/37 D．33/37
我猜測題有印刷錯誤,應是:1/2 7/9 13/16 19/23 5/6 ( )A．10/11 B．11/12 c．31/37 D．33/37 答案是31/37.理由:1/2 ,7/9 ,13/16 ,19/23 ,25/30 ,31/37,.....An=(6n-5)/(7n-5)分子和分母各為一等差數列,