1) \(3\frac{1}{12}\) = \(\frac{3 \times 12 + 1}{12} = \frac{36 + 1}{12} = \frac{37}{12}\).
2) \(4\frac{4}{7}\) = \(\frac{4 \times 7 + 4}{7} = \frac{28 + 4}{7} = \frac{32}{7}\).
3) \(15\frac{23}{10}\) = \(\frac{15 \times 10 + 23}{10} = \frac{150 + 23}{10} = \frac{173}{10}\).
Ответ: 1) \(\frac{37}{12}\); 2) \(\frac{32}{7}\); 3) \(\frac{173}{10}\)