Решите уравнение: 81x^3+36x^2+4x=0.

\[81x³ + 36x² + 4x = 0\]

\[x(9x + 2)^{2} = 0\]

\[x = 0\ \ \ \ \ \ \ \ \ \ 9x + 2 = 0\]

\[\ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ 9x = - 2\ \]

\[\ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ x = - \frac{2}{9}\]

\[Ответ:x = 0;\ x = - \frac{2}{9}.\]