tính theo cách thuận tiện nhất 3/5 / 5/6 / 6/7 / 7/8 + 2/5 + 23/35 mọi ng chỉ mik vs

\(\dfrac{3}{5} :\dfrac{ 5}{6}: \dfrac{ 6}{7} :\dfrac{ 7}{8} + \dfrac{2}{5} + \dfrac{23}{35}\)

\(=\dfrac{3}{5}\times\dfrac{6}{5}\times\dfrac{7}{6}\times\dfrac{8}{7} + \dfrac{2}{5} + \dfrac{23}{35}\)

\(=\dfrac{3\times8}{5\times5} + \dfrac{2}{5} + \dfrac{23}{35}\)

\(=\dfrac{24}{25} + \dfrac{2}{5} + \dfrac{23}{35}\)

\(=\dfrac{1}{5}(\dfrac{24}{5} + 2 + \dfrac{23}{7})\)

\(=\dfrac{1}{5}(\dfrac{24\times7+2\times35+23\times5}{35})\)

\(=\dfrac{1}{5}\times\dfrac{353}{35}\)

\(=\dfrac{353}{175}\).

`3/5 : 5/6 : 6/7 : 7/8 + 2/5 + 23/35`

`= 3/5 . 6/5 . 7/6 . 8/7+ 2/5 + 23/35`

`= 24/25 + 2/5 + 23/35`

`= 1/5 (24/5 + 2 + 23/7)`

`= 1/5 (24/5 + 2 + 23/7)`

`= 1/5 . 353/35`

`= 353/175`

(Chúc bạn hock tốt)