\[\boxed{\mathbf{2.2}\mathbf{69}}\]
Пояснение.
Решение.
\[\textbf{а)}\ \frac{2}{3} \cdot \frac{5}{11} = \frac{2 \cdot 5}{3 \cdot 11} = \frac{10}{33}\]
\[\textbf{б)}\ \frac{2}{9} \cdot \frac{5}{11} = \frac{2 \cdot 5}{9 \cdot 11} = \frac{10}{99}\]
\[\textbf{в)}\ \frac{7}{12} \cdot \frac{5}{6} = \frac{7 \cdot 5}{12 \cdot 6} = \frac{35}{72}\]
\[\textbf{г)}\ \frac{5}{7} \cdot \frac{5}{6} = \frac{5 \cdot 5}{7 \cdot 6} = \frac{25}{42}\]
\[\textbf{д)}\ \frac{1}{2} \cdot \frac{5}{9} = \frac{1 \cdot 5}{2 \cdot 9} = \frac{5}{18}\]
\[\textbf{е)}\ \frac{11}{12} \cdot \frac{7}{9} = \frac{11 \cdot 7}{12 \cdot 9} = \frac{77}{108}\]