1. Выполните действия: a) $$\frac{1}{7} + \frac{2}{7} + \frac{1}{14}$$ б) $$\frac{5}{6} - \frac{2}{3}$$ в) $$2,6 - 4$$ г) $$6 \frac{4}{9} + 2 \frac{2}{9}$$

a) $$\frac{1}{7} + \frac{2}{7} + \frac{1}{14} = \frac{2}{14} + \frac{4}{14} + \frac{1}{14} = \frac{2+4+1}{14} = \frac{7}{14} = \frac{1}{2}$$ б) $$\frac{5}{6} - \frac{2}{3} = \frac{5}{6} - \frac{4}{6} = \frac{5-4}{6} = \frac{1}{6}$$ в) $$2,6 - 4 = -1,4$$ г) $$6 \frac{4}{9} + 2 \frac{2}{9} = 6 + \frac{4}{9} + 2 + \frac{2}{9} = 8 + \frac{6}{9} = 8 + \frac{2}{3} = 8 \frac{2}{3}$$ Ответ: a) 1/2; б) 1/6; в) -1,4; г) $$8 \frac{2}{3}$$