Реши уравнение: 7/13-a=7/26.

\[\frac{7}{13} - a = \frac{7}{26}\]

\[a = \frac{7^{\backslash 2}}{13} - \frac{7}{26}\]

\[a = \frac{14 - 7}{26}\]

\[a = \frac{7}{26}.\]

\[Ответ:\ \ a = \frac{7}{26}.\]