1/3 × 2/5+1/5 2/7+1/7 2/9+……1/99 × 2/101
来源：学生作业帮助网 编辑：六六作业网 时间：2024/12/25 13:20:32
1/3×2/5+1/52/7+1/72/9+……1/99×2/1011/3×2/5+1/52/7+1/72/9+……1/99×2/1011/3×2/5+1/52/7+1/72/9+……1/99×2/1
1/3 × 2/5+1/5 2/7+1/7 2/9+……1/99 × 2/101
1/3 × 2/5+1/5 2/7+1/7 2/9+……1/99 × 2/101
1/3 × 2/5+1/5 2/7+1/7 2/9+……1/99 × 2/101
1/3 × 2/5+1/5 ×2/7+1/7 ×2/9+……1/99 × 2/101
=1/3-1/5+1/5-1/7+1/7-1/9+.+1/99-1/101
=1-1/101
=100/101