\[3x^{2} - x - 2 = 0\]
\[D = 1 + 24 = 25\]
\[x_{1} = \frac{1 + 5}{6} = \frac{6}{6} = 1;\ \ \ \]
\[x_{2} = \frac{1 - 5}{6} = - \frac{4}{6} = - \frac{2}{3}.\]
\[3x^{2} - x - 2 =\]
\[= 3 \cdot \left( x + \frac{2}{3} \right)(x - 1) =\]
\[= (3x + 2)(x - 1).\]