1. Выполните действие: a) 7 3/14 : 3/39; б) 1 11/24 * 1 5/17; в) 2 3/16 * 4/5; г) 11 * 5 7/33.

a)

$$ 7 \frac{3}{14} : \frac{3}{39} = \frac{7 \cdot 14 + 3}{14} : \frac{3}{39} = \frac{98 + 3}{14} : \frac{3}{39} = \frac{101}{14} : \frac{3}{39} = \frac{101}{14} \cdot \frac{39}{3} = \frac{101}{14} \cdot \frac{13}{1} = \frac{1313}{14} = 93 \frac{11}{14} $$

б)

$$ 1 \frac{11}{24} \cdot 1 \frac{5}{17} = \frac{1 \cdot 24 + 11}{24} \cdot \frac{1 \cdot 17 + 5}{17} = \frac{24 + 11}{24} \cdot \frac{17 + 5}{17} = \frac{35}{24} \cdot \frac{22}{17} = \frac{35}{12} \cdot \frac{11}{17} = \frac{385}{204} = 1 \frac{181}{204} $$

в)

$$ 2 \frac{3}{16} \cdot \frac{4}{5} = \frac{2 \cdot 16 + 3}{16} \cdot \frac{4}{5} = \frac{32 + 3}{16} \cdot \frac{4}{5} = \frac{35}{16} \cdot \frac{4}{5} = \frac{7}{4} \cdot \frac{1}{1} = \frac{7}{4} = 1 \frac{3}{4} $$

г)

$$ 11 \cdot 5 \frac{7}{33} = 11 \cdot \frac{5 \cdot 33 + 7}{33} = 11 \cdot \frac{165 + 7}{33} = 11 \cdot \frac{172}{33} = \frac{1}{3} \cdot \frac{172}{1} = \frac{172}{3} = 57 \frac{1}{3} $$ Ответ: a) $$93 \frac{11}{14}$$, б) $$1 \frac{181}{204}$$, в) $$1 \frac{3}{4}$$, г) $$57 \frac{1}{3}$$