\(\dfrac{5}{7}=\dfrac{20}{28}\\ \dfrac{3}{4}=\dfrac{21}{28}\)
Vì \(\dfrac{20}{28}< \dfrac{21}{28}\Rightarrow\dfrac{5}{7}< \dfrac{3}{4}\)
\(\dfrac{5}{7}=\dfrac{5\times4}{7\times4}=\dfrac{20}{28}\)
\(\dfrac{3}{4}=\dfrac{3\times7}{4\times7}=\dfrac{21}{28}\)
\(\Rightarrow\dfrac{20}{28}< \dfrac{21}{28}\) hay \(\dfrac{5}{6}< \dfrac{3}{4}\)