\(=\frac{1}{1.6}+\frac{1}{6.11}+\frac{1}{11.16}+\frac{1}{16.21}+...+\frac{1}{41.46}\)
\(=\frac{1}{5}\left(1-\frac{1}{6}+\frac{1}{6}-\frac{1}{11}+\frac{1}{11}-\frac{1}{16}+...+\frac{1}{41}-\frac{1}{46}\right)\)
=\(\frac{1}{5}\left(1-\frac{1}{46}\right)=\frac{1}{5}x\frac{45}{46}=\frac{9}{46}\)
Cảm ơn nhé . Mình đang cần . Mình k rồi đó bạn ơi .