ta có : `2/5 = (2xx2)/(5xx2)=4/10 ; 5/2=(5xx5)/(2xx5)= 25/10`
`=> 2/5 < 5/2`
\(\dfrac{2}{5}=\dfrac{2\times2}{5\times2}=\dfrac{4}{10}\)
\(\dfrac{5}{2}=\dfrac{5\times5}{2\times5}=\dfrac{25}{10}\)
\(=>\dfrac{2}{5}< \dfrac{5}{2}\)
= \(\dfrac{4}{10}\)...\(\dfrac{25}{10}\)
= <