Điền dấu (\(<;\,>;\,=\)) thích hợp vào ô trống:

$\left( {\dfrac{2}{5} + \dfrac{7}{8}} \right):17\,\,\,\,$

$\,\,\,\dfrac{{11}}{{14}}:\dfrac{{55}}{7}$

Ta có:

$\begin{array}{l} +) \,\left( {\dfrac{2}{5} + \dfrac{7}{8}} \right):17\, = \left( {\dfrac{{16}}{{40}} + \dfrac{{35}}{{40}}} \right):17\, = \dfrac{{51}}{{40}}:17 = \dfrac{{51}}{{40 \times 17}} = \dfrac{{17 \times 3}}{{40 \times 17}} = \dfrac{3}{{40}};\\+) \,\dfrac{{11}}{{14}}:\dfrac{{55}}{7} = \dfrac{{11}}{{14}} \times \dfrac{7}{{55}} = \dfrac{{11 \times 7}}{{14 \times 55}} = \dfrac{{11 \times 7}}{{7 \times 2 \times 11 \times 5}} = \dfrac{1}{{10}}= \dfrac{4}{{40}}\end{array}$

Mà \(\dfrac{3}{{40}} < \dfrac{4}{{40}}\) , hay \(\dfrac{3}{{40}} < \dfrac{1}{{10}}\)

Do đó $\left( {\dfrac{2}{5} + \dfrac{7}{8}} \right):17\,\,\,\, < \,\,\,\,\,\,\dfrac{{11}}{{14}}:\dfrac{{55}}{7}$

Vậy dấu thích hợp điền vào ô trống là \( < \).