\[ \frac{5}{13} \times 7 + \frac{8}{13} \times 7 = 7 \times \left(\frac{5}{13} + \frac{8}{13}\right) \]
\[ \frac{5}{13} + \frac{8}{13} = \frac{5 + 8}{13} = \frac{13}{13} = 1 \]
\[ 7 \times 1 = 7 \]
Ответ: 7