2. Вычисли: a) -2,5 - (-1 2/3 + 2 1/3); б) -4,544 - (2,76 - 1,386); в) 3 2/19 - (-7/19 - 1 1/2).

a) $$-2,5 - (-1\frac{2}{3} + 2\frac{1}{3}) = -2,5 - (\frac{-5}{3} + \frac{7}{3}) = -2,5 - \frac{2}{3} = -2,5 - 0,666... = -3,166... \approx -3,17$$ б) -4,544 - (2,76 - 1,386) = -4,544 - 1,374 = -5,918 в) $$3\frac{2}{19} - (-\frac{7}{19} - 1\frac{1}{2}) = \frac{59}{19} - (-\frac{7}{19} - \frac{3}{2}) = \frac{59}{19} + \frac{7}{19} + \frac{3}{2} = \frac{66}{19} + \frac{3}{2} = \frac{132}{38} + \frac{57}{38} = \frac{189}{38} = 4\frac{37}{38}$$ **Ответ:** a) -3,17 б) -5,918 в) 4 37/38