- a) \(\frac{12}{35} \cdot \frac{7}{18} = \frac{12 \cdot 7}{35 \cdot 18} = \frac{2 \cdot 6 \cdot 7}{5 \cdot 7 \cdot 6 \cdot 3} = \frac{2}{5 \cdot 3} = \frac{2}{15}\)
- б) \(1\frac{7}{33} \cdot 1\frac{7}{15} = \frac{40}{33} \cdot \frac{22}{15} = \frac{40 \cdot 22}{33 \cdot 15} = \frac{8 \cdot 5 \cdot 2 \cdot 11}{3 \cdot 11 \cdot 3 \cdot 5} = \frac{8 \cdot 2}{3 \cdot 3} = \frac{16}{9} = 1\frac{7}{9}\)
- в) \(2\frac{7}{13} \cdot 1\frac{11}{15} = \frac{33}{13} \cdot \frac{26}{15} = \frac{33 \cdot 26}{13 \cdot 15} = \frac{11 \cdot 3 \cdot 2 \cdot 13}{13 \cdot 3 \cdot 5} = \frac{11 \cdot 2}{5} = \frac{22}{5} = 4\frac{2}{5}\)
- г) \(4\frac{7}{18} \cdot 9 = \frac{79}{18} \cdot 9 = \frac{79 \cdot 9}{18} = \frac{79 \cdot 9}{2 \cdot 9} = \frac{79}{2} = 39\frac{1}{2}\)
Ответ: a) \(\frac{2}{15}\); б) \(1\frac{7}{9}\); в) \(4\frac{2}{5}\); г) \(39\frac{1}{2}\)