1) При a = 12:
* \(\frac{12}{12} + \frac{8}{12} = 1 + \frac{2}{3} = \frac{3}{3} + \frac{2}{3} = \frac{5}{3}\)
2) При a = 8:
* \(\frac{8}{12} + \frac{8}{8} = \frac{2}{3} + 1 = \frac{2}{3} + \frac{3}{3} = \frac{5}{3}\)
3) При a = 4:
* \(\frac{4}{12} + \frac{8}{4} = \frac{1}{3} + 2 = \frac{1}{3} + \frac{6}{3} = \frac{7}{3}\)
**Ответ:**
При a = 12: 5/3
При a = 8: 5/3
При a = 4: 7/3