\[\frac{2\frac{6}{7}}{3\frac{3}{14}} = 2\frac{6}{7}\ :3\frac{3}{14} = \frac{20}{7}\ :\frac{45}{14} = \frac{20}{7} \cdot \frac{14}{45} =\]
\[= \frac{4 \cdot 5 \cdot 7 \cdot 2}{7 \cdot 5 \cdot 9} = \frac{8}{9}\]