1/3*5+1/5*7+1/7*9+………+1/101*103的值

題目：

1/3*5+1/5*7+1/7*9+………+1/101*103的值

解答：

1/3*5+1/5*7+1/7*9+………+1/101*103
=1/2[(1/3-1/5)+(1/5-1/7)+(1/7-1/9)+……+(1/101-1/103)]
=1/2[1/3-1/103]
=50/309