2. 12 20

• $$\frac{13}{12} - \frac{13}{20} = \frac{13 \cdot 5}{12 \cdot 5} - \frac{13 \cdot 3}{20 \cdot 3} = \frac{65}{60} - \frac{39}{60} = \frac{26}{60} = \frac{13}{30}$$

Ответ: $$\frac{13}{30}$$