1/2×3+1/3×4+1/4×5······﹢1/49×50

问题描述:

1/2×3+1/3×4+1/4×5······﹢1/49×50

1/2×3+1/3×4+1/4×5······﹢1/49×50
=1/2-1/3 + 1/3-1/4 + 1/4-1/5+...+1/49-1/50
=1/2-1/50
=12/25不用谢哦 用裂项想减法解决~哦,我采纳你