Question

2/35+ 4/77+ 2/143+ 4/221+ 2/323+ 4/437+ 2/575

Giải hộ tui bài này tôi like cho

Answer 1

2/35 + 4/77 + 2/143 + 4/221 + 2/323 + 4/437 + 2/575 

= 2/5.7 + 4/7.11 + 2/11.13 + 4/13.17 + 2/17.19 + 4/19.23 + 2/23.25 

= 1/5 - 1/7 + 1/7 - 1/11 + 1/11 - 1/13 + 1/13 - 1/17 + 1/17 - 1/19 + 1/19 - 1/23 + 1/23 - 1/15 

= 1/5 - 1/25 

= 4/25 

Answer 2

\(\frac{2}{35}\)+ \(\frac{4}{77}\)+ \(\frac{2}{143}\)+ \(\frac{4}{221}\)+ \(\frac{2}{323}\)+ \(\frac{4}{437}\)+ \(\frac{2}{575}\).

= \(\frac{2}{5.7}\)+ \(\frac{4}{7.11}\)+ \(\frac{2}{11.13}\)+ \(\frac{4}{13.17}\)+ \(\frac{4}{17.21}\)+ \(\frac{2}{21.23}\).

= \(\frac{1}{5}\)- \(\frac{1}{7}\)+ \(\frac{1}{7}\)- \(\frac{1}{11}\)+ \(\frac{1}{11}\)- \(\frac{1}{13}\)+ \(\frac{1}{13}\)- \(\frac{1}{17}\)+ \(\frac{1}{17}\)- \(\frac{1}{21}\)+ \(\frac{1}{21}\)- \(\frac{1}{23}\).

= \(\frac{1}{5}\)- \(\frac{1}{23}\).

= \(\frac{23}{115}\)- \(\frac{5}{115}\).

= \(\frac{18}{115}\).