Вычислите: \(\frac{4}{9}+1\frac{2}{3}\); \(3\frac{1}{2}-1\frac{2}{5}\); \(4\frac{3}{7}\cdot\frac{12}{73}\); \(18\frac{1}{2}\cdot2\frac{3}{4}\).

1. \(\frac{4}{9}+1\frac{2}{3}=\frac{4}{9}+\frac{5}{3}=\frac{4}{9}+\frac{15}{9}=\frac{19}{9}=2\frac{1}{9}\).
2. \(3\frac{1}{2}-1\frac{2}{5}=\frac{7}{2}-\frac{7}{5}=\frac{35-14}{10}=\frac{21}{10}=2\frac{1}{10}\).
3. \(4\frac{3}{7}\cdot\frac{12}{73}=\frac{31}{7}\cdot\frac{12}{73}=\frac{372}{511}\).
4. \(18\frac{1}{2}\cdot2\frac{3}{4}=\frac{37}{2}\cdot\frac{11}{4}=\frac{407}{8}=50\frac{7}{8}\).

Ответ: \(2\frac{1}{9};\ 2\frac{1}{10};\ \frac{372}{511};\ 50\frac{7}{8}\).