2. Вычислите: a) $$\frac{2}{3} - \frac{1}{6}$$; б) $$-\frac{1}{3} - \frac{2}{5}$$; в) $$\frac{3}{8} + \frac{1}{2}$$.

Решение: a) $$\frac{2}{3} - \frac{1}{6} = \frac{4}{6} - \frac{1}{6} = \frac{3}{6} = \frac{1}{2}$$ = **0.5** б) $$-\frac{1}{3} - \frac{2}{5} = -\frac{5}{15} - \frac{6}{15} = -\frac{11}{15}$$ = **-0.7333** в) $$\frac{3}{8} + \frac{1}{2} = \frac{3}{8} + \frac{4}{8} = \frac{7}{8}$$ = **0.875**