1/1×3+1/3×5+1/5×7+1/7×9……1/97×99算式,

问题描述:

1/1×3+1/3×5+1/5×7+1/7×9……1/97×99
算式,

49/99
1/2(1-1/3+1/3-1/5+1/5-1/7+...+1/97-1/99 )
=1/2(1-1/99)=49/99
裂项求和