1998分之1997乘998
=(1-1/1998)×998
=998-998/1998
=997又499/999
简便计算:
1998分之1997×998
=1998分之(1998-1)×998
=1×998-1998分之1×998
=998-999分之499(即1998分之998)
=997又999分之500
(望采纳,谢谢)
1997/1998×998
=(1998-1)/1998×998
=(1-1/1998)×998
=1×998-(1/1998)×998
=998-998/1998
=997又500/999
1997/1998*988
=(1998-1)/1998*988
=988-988/1998
=987又1000/1998