Задание 14

a) $$\frac{1}{5} + \frac{53}{50} = \frac{10}{50} + \frac{53}{50} = \frac{63}{50} = 1\frac{13}{50}$$

б) $$\frac{12}{25} \cdot \frac{5}{16} = \frac{12 \cdot 5}{25 \cdot 16} = \frac{3 \cdot 1}{5 \cdot 4} = \frac{3}{20}$$

в) $$\frac{12}{5} : \frac{15}{2} = \frac{12}{5} \cdot \frac{2}{15} = \frac{12 \cdot 2}{5 \cdot 15} = \frac{4 \cdot 2}{5 \cdot 5} = \frac{8}{25}$$

г) $$\frac{1}{4} - \frac{51}{20} = \frac{5}{20} - \frac{51}{20} = \frac{-46}{20} = -\frac{23}{10} = -2\frac{3}{10}$$