13. Вычислите: $$2\frac{-1}{20} - \frac{1}{6} \cdot 5\frac{3}{10} + 5 : 1\frac{1}{2}$$

Решим пример по действиям: 1. $$2\frac{-1}{20} = \frac{2 \cdot 20 - 1}{20} = \frac{40-1}{20} = \frac{39}{20}$$ 2. $$5\frac{3}{10} = \frac{5 \cdot 10 + 3}{10} = \frac{50 + 3}{10} = \frac{53}{10}$$ 3. $$\frac{1}{6} \cdot \frac{53}{10} = \frac{1 \cdot 53}{6 \cdot 10} = \frac{53}{60}$$ 4. $$1\frac{1}{2} = \frac{1 \cdot 2 + 1}{2} = \frac{3}{2}$$ 5. $$5 : \frac{3}{2} = 5 \cdot \frac{2}{3} = \frac{5 \cdot 2}{3} = \frac{10}{3}$$ 6. $$\frac{39}{20} - \frac{53}{60} + \frac{10}{3} = \frac{39 \cdot 3}{20 \cdot 3} - \frac{53}{60} + \frac{10 \cdot 20}{3 \cdot 20} = \frac{117}{60} - \frac{53}{60} + \frac{200}{60} = \frac{117 - 53 + 200}{60} = \frac{264}{60} = \frac{264:12}{60:12} = \frac{22}{5} = 4\frac{2}{5} = 4.4$$ Ответ: $$4\frac{2}{5}$$ или 4.4