Ответ:

а) \(\frac{1}{2} − \frac{1}{5} = \frac{5}{10} − \frac{2}{10} = \frac{3}{10}\).

б) \(0.5 \cdot 0.06 + 1.3 = 0.03 + 1.3 = 1.33\).

в) \((3\frac{1}{4} + \frac{5}{12}) : \frac{5}{6} = (\frac{13}{4} + \frac{5}{12}) : \frac{5}{6} = (\frac{39}{12} + \frac{5}{12}) : \frac{5}{6} = \frac{44}{12} : \frac{5}{6} = \frac{11}{3} \cdot \frac{6}{5} = \frac{22}{5} = 4.4\).

Ответ: а) \(\frac{3}{10}\); б) 1,33; в) \(\frac{22}{5}\) (4,4).