2.\newline2\frac{4}{7}-\frac{5}{21}+(5\frac{1}{3}-3\frac{2}{5})\cdot\frac{9}{20}\cdot\frac{11}{18}

1. $$2\frac{4}{7} - \frac{5}{21} = \frac{18}{7} - \frac{5}{21} = \frac{18 \cdot 3}{7 \cdot 3} - \frac{5}{21} = \frac{54}{21} - \frac{5}{21} = \frac{49}{21} = \frac{7}{3}$$

2. $$5\frac{1}{3} - 3\frac{2}{5} = \frac{16}{3} - \frac{17}{5} = \frac{16 \cdot 5}{3 \cdot 5} - \frac{17 \cdot 3}{5 \cdot 3} = \frac{80}{15} - \frac{51}{15} = \frac{29}{15}$$

3. $$\frac{29}{15} \cdot \frac{9}{20} \cdot \frac{11}{18} = \frac{29}{15} \cdot \frac{1}{20} \cdot \frac{11}{2} = \frac{29 \cdot 11}{15 \cdot 20 \cdot 2} = \frac{319}{600}$$

4. $$\frac{7}{3} + \frac{319}{600} = \frac{7 \cdot 200}{3 \cdot 200} + \frac{319}{600} = \frac{1400}{600} + \frac{319}{600} = \frac{1719}{600} = \frac{573}{200} = 2\frac{173}{200}$$

Ответ: $$2\frac{173}{200}$$