1. Найдите произведение: 5 7 6 9 a) 11 7 28 33 ; 6) 1 8 4 25 ; в) 3 7 11 13 ; г) 2 6 3 9 ; д)

a) $$ \frac{5}{6} \cdot \frac{7}{9} = \frac{5 \cdot 7}{6 \cdot 9} = \frac{35}{54} $$.

б) $$ \frac{11}{28} \cdot \frac{7}{33} = \frac{11 \cdot 7}{28 \cdot 33} = \frac{1 \cdot 1}{4 \cdot 3} = \frac{1}{12} $$.

в) $$ 1\frac{1}{8} \cdot 4\frac{25}{100} = \frac{9}{8} \cdot \frac{425}{100} = \frac{9 \cdot 17}{8 \cdot 4} = \frac{153}{32} = 4\frac{25}{32} $$.

г) $$ 3\frac{7}{11} \cdot 1\frac{1}{13} = \frac{40}{11} \cdot \frac{14}{13} = \frac{560}{143} = 3\frac{131}{143} $$.

д) $$ 2\frac{6}{3} \cdot 2\frac{6}{9} = 4 \cdot 2\frac{2}{3} = 4 \cdot \frac{8}{3} = \frac{32}{3} = 10\frac{2}{3} $$.

Ответ: a) $$ \frac{35}{54} $$, б) $$ \frac{1}{12} $$, в) $$4\frac{25}{32}$$, г) $$3\frac{131}{143}$$, д) $$10\frac{2}{3}$$