a) $$1\frac{1}{3} \cdot 1\frac{1}{5} = \frac{4}{3} \cdot \frac{6}{5} = \frac{4 \cdot 2}{1 \cdot 5} = \frac{8}{5} = 1\frac{3}{5}$$
Ответ: $$1\frac{3}{5}$$
б) $$2\frac{4}{9} \cdot 3\frac{3}{11} = \frac{22}{9} \cdot \frac{36}{11} = \frac{2 \cdot 4}{1 \cdot 1} = 8$$
Ответ: $$8$$
в) $$1\frac{1}{5} \cdot 1\frac{7}{9} = \frac{6}{5} \cdot \frac{16}{9} = \frac{2 \cdot 16}{5 \cdot 3} = \frac{32}{15} = 2\frac{2}{15}$$
Ответ: $$2\frac{2}{15}$$
г) $$1\frac{4}{21} \cdot 4\frac{1}{5} = \frac{25}{21} \cdot \frac{21}{5} = \frac{5 \cdot 1}{1 \cdot 1} = 5$$
Ответ: $$5$$
д) $$2\frac{2}{7} \cdot 1\frac{3}{4} = \frac{16}{7} \cdot \frac{7}{4} = \frac{4 \cdot 1}{1 \cdot 1} = 4$$
Ответ: $$4$$