[tex]LCM(6,\ 5)=30\\\\\begin{array}{ccc}\dfrac{2}{6}=\dfrac{2\cdot5}{6\cdot5}=\dfrac{10}{30}\\\\\dfrac{4}{5}=\dfrac{4\cdot6}{5\cdot6}=\dfrac{24}{30}\end{array}\Rightarrow\dfrac{10}{30} < \dfrac{24}{30}\\.\\\\Answer:\ \dfrac{2}{6} < \dfrac{4}{5}[/tex]
Other method:
[tex]\dfrac{2}{6} < \dfrac{1}{2}\ (half)\\\\\dfrac{4}{5} > \dfrac{1}{2}\ (half)\\\\therefore\\\\\dfrac{2}{6} < \dfrac{4}{5}[/tex]
[tex]\dfrac{2}{6}\ is\ less\ than\ \dfrac{4}{5}[/tex]