\[\boxed{\mathbf{2.2}\mathbf{85}}\]
Пояснение.
Решение.
\[\textbf{а)}\ 2\frac{3}{4} \cdot \frac{3}{7} = \frac{11}{4} \cdot \frac{3}{7} = \frac{11 \cdot 3}{4 \cdot 7} =\]
\[= \frac{33}{28} = 1\frac{5}{28}\]
\[\textbf{б)}\ \frac{5}{9} \cdot 1\frac{2}{3} = \frac{5}{9} \cdot \frac{5}{3} = \frac{5 \cdot 5}{9 \cdot 3} = \frac{25}{27}\]
\[\textbf{в)}\ 3\frac{4}{5} \cdot \frac{5}{11} = \frac{19}{5} \cdot \frac{5}{11} = \frac{19 \cdot 5}{5 \cdot 11} =\]
\[= \frac{19}{11} = 1\frac{8}{11}\]
\[\textbf{г)}\ 3\frac{1}{9} \cdot \frac{3}{7} = \frac{28}{9} \cdot \frac{3}{7} = \frac{28 \cdot 3}{9 \cdot 7} =\]
\[= \frac{4 \cdot 1}{3 \cdot 1} = \frac{4}{3} = 1\frac{1}{3}\]
\[\textbf{д)}\ 1\frac{5}{8} \cdot \frac{8}{13} = \frac{13}{8} \cdot \frac{8}{13} = \frac{13 \cdot 8}{8 \cdot 13} =\]
\[= 1\]
\[\textbf{е)}\ \frac{13}{24} \cdot 1\frac{11}{13} = \frac{13}{24} \cdot \frac{24}{13} =\]
\[= \frac{13 \cdot 24}{24 \cdot 13} = 1\]