1/2*1/3+1/3*1/4+1/4*1/5+.......+1/99*1/100
1/2*1/3+1/3*1/4+1/4*1/5+.......+1/99*1/100
日期：2022-01-31 13:19:04 人气：1
=1/2×3+1/3×4+1/4×5+……+1/99×100
=1/2-1/3+1/3-1/4+1/4-1/5+……+1/99-1/100
=1/2-1/100
=50/100-1/100
=49/100
=1/2-1/3+1/3-1/4+1/4-1/5+……+1/99-1/100
=1/2-1/100
=50/100-1/100
=49/100