Вычислите: 1) $$\frac{2}{5} - \frac{4}{5}$$ 2) $$1870 - \frac{5}{22}$$ 3) $$5\frac{1}{5} - 6\frac{1}{6}$$

Выполним вычисления по действиям: 1) $$\frac{2}{5} - \frac{4}{5} = \frac{2-4}{5} = \frac{-2}{5} = -\frac{2}{5}$$ 2) $$1870 - \frac{5}{22} = \frac{1870 \cdot 22}{22} - \frac{5}{22} = \frac{41140 - 5}{22} = \frac{41135}{22} = 1869\frac{17}{22}$$ 3) $$5\frac{1}{5} - 6\frac{1}{6} = \frac{5 \cdot 5 + 1}{5} - \frac{6 \cdot 6 + 1}{6} = \frac{26}{5} - \frac{37}{6} = \frac{26 \cdot 6}{5 \cdot 6} - \frac{37 \cdot 5}{6 \cdot 5} = \frac{156}{30} - \frac{185}{30} = \frac{156 - 185}{30} = \frac{-29}{30} = -\frac{29}{30}$$ Ответ: 1) $$\frac{2}{5} - \frac{4}{5} = -\frac{2}{5}$$ 2) $$1870 - \frac{5}{22} = 1869\frac{17}{22}$$ 3) $$5\frac{1}{5} - 6\frac{1}{6} = -\frac{29}{30}$$