5. Выполните действие: a) б) -+ в) г) 1,2-12,3; д) -0,25-(-1,2); e) -17,9+3,12.

Решение:

a) \[-\frac{1}{6} + \frac{2}{3} = -\frac{1}{6} + \frac{4}{6} = \frac{3}{6} = \frac{1}{2} = 0.5\]

б) \[-\frac{4}{5} + (-\frac{1}{10}) = -\frac{8}{10} - \frac{1}{10} = -\frac{9}{10} = -0.9\]

в) \[-\frac{3}{8} - \frac{3}{4} = \frac{3}{8} - \frac{6}{8} = -\frac{3}{8} = -0.375\]

г) \[1.2 - 12.3 = -11.1\]

д) \[-0.25 - (-1.2) = -0.25 + 1.2 = 0.95\]

e) \[-17.9 + 3.12 = -14.78\]