Решение:
\[ \frac{13}{9} \]
\[ \frac{7}{3} \]
\[ \frac{2}{7} \]
\[ \frac{13}{9} = \frac{13 \times 7}{9 \times 7} = \frac{91}{63} \]
\[ \frac{7}{3} = \frac{7 \times 21}{3 \times 21} = \frac{147}{63} \]
\[ \frac{2}{7} = \frac{2 \times 9}{7 \times 9} = \frac{18}{63} \]
\[ \frac{91}{63} + \frac{147}{63} + \frac{18}{63} = \frac{91 + 147 + 18}{63} = \frac{256}{63} \]
Ответ:
\[ \frac{256}{63} \]