\[0,3x^{2} + 0,1x = 0\ \ \ \ \ | \cdot 10\]
\[3x^{2} + x = 0\]
\[x(3x + 1) = 0\]
\[x = 0\ \ \ \ \ \ 3x = - 1\]
\[\ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ x = - \frac{1}{3}\]
\[Ответ:x = 0;\ \ x = - \frac{1}{3}.\]