\[x = \frac{1}{3}\ \ и\ \ x = - \frac{1}{6}:\]
\[\left( x - \frac{1}{3} \right)\left( x + \frac{1}{6} \right) = 0\]
\[x^{2} + \frac{1}{6}x - \frac{1}{3}x - \frac{1}{18} = 0\]
\[x^{2} - \frac{1}{6}x - \frac{1}{18} = 0\ \ \ \ \ | \cdot 18\]
\[18x^{2} - 3x - 1 = 0\]