Question

Các bạn tình hộ mình,có lời giải rõ ràng nhé!

1/6+1/12+1/20+1/30+1/42+1/56

 

Answer 1

Ta có : \(\frac{1}{2.3}+\frac{1}{3.4}+\frac{1}{4.5}+\frac{1}{5.6}+\frac{1}{6.7}+\frac{1}{7.8}\)

\(=\frac{1}{2}-\frac{1}{3}+\frac{1}{3}-\frac{1}{4}+......+\frac{1}{7}-\frac{1}{8}\)

\(=\frac{1}{2}-\frac{1}{8}\)

\(=\frac{4}{8}-\frac{1}{8}=\frac{3}{8}\)

Answer 2

1/6+1/12+1/20+1/30+1/42+1/56  = 3/8

nha bn 

Answer 3

Cảm ơn hai bạn!