Question

S=1/6+1/12+1/20+1/30+1/42+1/56+1/72+1/90+1/110

Answer 1

\(\Rightarrow\)S\(=\)9/22  nha bạn,mình tính nhần

Answer 2

\(\frac{10}{11}\)nha bạn mình giải rồi

Answer 3

S\(=\)1/2.3 + 1/3.4 + 1/4.5 + 1/5.6 + 1/6.7 + 1/7.8 + 1/8.9 + 1/9.10 + 1/10.11

\(\rightarrow\)S\(=\)1/2-1/3+1/3-1/4+1/4-1/5+1/5-1/6+1/6-1/7+1/7-1/8+1/8-1/9+1/9-1/10+1/10-1/11

\(\rightarrow\)S\(=\)1/2-1/11

\(\rightarrow\)S\(=\)11/22-2/22

\(\Rightarrow\)S\(=\)7/22