Question

Giúp mk

Answer 1

\(\frac{1}{3}+\frac{1}{31}+\frac{1}{35}+\frac{1}{37}+\frac{1}{47}+\frac{1}{53}+\frac{1}{61}\)

\(< \frac{1}{3}+\frac{1}{30}.10+\frac{1}{45}.3\)

\(< \frac{1}{3}+\frac{1}{10}+\frac{1}{15}\)

\(< \frac{10}{30}+\frac{3}{30}+\frac{2}{30}=\frac{1}{2}\left(đpcm\right)\)

Answer 2

\(\frac{1}{3}+\frac{1}{31}+\frac{1}{35}+\frac{1}{37}+\frac{1}{47}+\frac{1}{53}+\frac{1}{61}\)

\(< \frac{1}{3}+\frac{1}{30}.3+\frac{1}{45}.3\)

\(< \frac{1}{3}+\frac{1}{10}+\frac{1}{15}\)

\(< \frac{10}{30}+\frac{3}{30}+\frac{2}{30}=\frac{1}{2}\left(đpcm\right)\)