96. Выполните действие: a) $$\frac{3}{7} × 2\frac{2}{5}$$; б) $$3\frac{1}{9} × 2\frac{1}{7}$$; в) $$\frac{7}{13} × 3\frac{9}{56}$$; г) $$2\frac{1}{7} × 2\frac{4}{5}$$

Решение:

1. \(\frac{3}{7} × 2\frac{2}{5} = \frac{3}{7} × \frac{12}{5} = \frac{36}{35}\)
2. \(3\frac{1}{9} × 2\frac{1}{7} = \frac{28}{9} × \frac{15}{7} = \frac{4 × 15}{9} = \frac{60}{9} = \frac{20}{3}\)
3. \(\frac{7}{13} × 3\frac{9}{56} = \frac{7}{13} × \frac{3 × 56 + 9}{56} = \frac{7}{13} × \frac{168+9}{56} = \frac{7}{13} × \frac{177}{56} = \frac{1}{13} × \frac{177}{8} = \frac{177}{104}\)
4. \(2\frac{1}{7} × 2\frac{4}{5} = \frac{15}{7} × \frac{14}{5} = \frac{3 × 2}{1} = 6\)

Ответ: а) $$\frac{36}{35}$$; б) $$\frac{20}{3}$$; в) $$\frac{177}{104}$$; г) 6.