Решите уравнение: (x+1)/(x-4)=(3x+1)/(3x-1).

\[\frac{x + 1}{x - 4} = \frac{3x + 1}{3x - 1}\]

\[\frac{x + 1^{\backslash 3x - 1}}{x - 4} - \frac{3x + 1^{\backslash x - 4}}{3x - 1} = 0\]

\[13x + 3 = 0\]

\[13x = - 3\]

\[x = - \frac{3}{13}\]

\[Ответ:\ x = - \frac{3}{13}.\]