Question

1/1998+2/1998+......1997/1998等于多少

Answer 1

1/1998+2/1998+......1997/1998
=(1+2+3+……+1997)/1998
=(1+1997+2+1996+……+998+1000+999)/1998
=(1998+1998+……+1998+999)/1998
总共是998个1998，
=(1998*998+999)/1998
=998+1/2
=1997/2

Answer 2

=[(1/1998+1997/1998)+(2/1998+1996/2998)......]+999/1998
=998+999/1998
=998又999/1998
=998又1/2

Answer 3

原式 = (1+2+......+1997)/1998
= 1997(1+1997)/1998*2
= 1997/2

Answer 4

1 2 3 . 1997 1998 1999等于多少 原式=（1 1999）×1999÷2=1000×1999=1999000 原式=（1 1999）×1999÷2=1999000 (1999 1)×（

Answer 5

=（1+2+3+......+1997)/1998
=(1+1997)*1997/1998
=1998*1997/1998
=1997/2