1) \(\frac{17}{12} - \frac{1}{6}\) 2) \(\frac{3}{10} + \frac{1}{15}\) 3) \(\frac{7}{13} \cdot \frac{89}{56}\) 4) \(\frac{12}{25} \cdot \frac{8}{15}\)

Решение:

1. \(\frac{17}{12} - \frac{1}{6} = \frac{17}{12} - \frac{2}{12} = \frac{17 - 2}{12} = \frac{15}{12} = \frac{5}{4}\)
2. \(\frac{3}{10} + \frac{1}{15} = \frac{9}{30} + \frac{2}{30} = \frac{9 + 2}{30} = \frac{11}{30}\)
3. \(\frac{7}{13} \cdot \frac{89}{56} = \frac{1}{13} \cdot \frac{89}{8} = \frac{89}{104}\)
4. \(\frac{12}{25} \cdot \frac{8}{15} = \frac{4}{25} \cdot \frac{8}{5} = \frac{32}{125}\)

Ответ: 1) \(\frac{5}{4}\); 2) \(\frac{11}{30}\); 3) \(\frac{89}{104}\); 4) \(\frac{32}{125}\).