Решите неравенство: (3x-1)/(3x+1)<=0.

\[\frac{3x - 1}{3x + 1} < 0\]

\[\frac{3\left( x - \frac{1}{3} \right)}{3\left( x + \frac{1}{3} \right)} < 0\]

\[- \frac{1}{3} < x < \frac{1}{3}.\]

\[Ответ:\ - \frac{1}{3} < x < \frac{1}{3}.\]