1. Вычислите: a) $$2\frac{1}{3}$$; б) $$1\frac{1}{9} \cdot 3$$; в) $$1\frac{2}{5}$$

a) $$2\frac{1}{3} = \frac{2 \cdot 3 + 1}{3} = \frac{6 + 1}{3} = \frac{7}{3}$$ б) $$1\frac{1}{9} \cdot 3 = \frac{1 \cdot 9 + 1}{9} \cdot 3 = \frac{10}{9} \cdot 3 = \frac{10 \cdot 3}{9} = \frac{30}{9} = \frac{10}{3}$$ в) $$1\frac{2}{5} = \frac{1 \cdot 5 + 2}{5} = \frac{5 + 2}{5} = \frac{7}{5}$$