如题所述
第1个回答 推荐于2020-12-11
1/2+1/6+1/12+1/20+1/30
=1-1/2+1/2-1/3+1/3-1/4+1/4-1/5+1/5-1/6
=1-1/6
=5/6本回答被提问者采纳
=1-1/2+1/2-1/3+1/3-1/4+1/4-1/5+1/5-1/6
=1-1/6
=5/6本回答被提问者采纳
第2个回答 2011-06-02
2=!*2
6=2*3
12=3*4
20=4*5
30=5*6
6=2*3
12=3*4
20=4*5
30=5*6
第3个回答 2011-06-02
1/2 + (1/2-1/3) + (1/3-1/4) + (1/4-1/5) + (1/5-1/6) = 1/2 + 1/2 - 1/6 = 5/6
