\[y = 3x^{2} + x - 17\]
\[y = 0:\]
\[3x^{2} + x - 17 = 0\]
\[D = 1 + 204 = 205\]
\[x_{1} = \frac{- 1 + \sqrt{205}}{6};\ \ \ \]
\[x_{2} = \frac{- 1 - \sqrt{205}}{6}\]
\[y = - 2x^{2} - 5x + 12\]
\[y = 0:\]
\[- 2x^{2} - 5x + 12 = 0\]
\[2x^{2} + 5x - 12 = 0\]
\[D = 25 + 96 = 121\]
\[x_{1} = \frac{- 5 + 11}{4} = 1,5;\ \ \]
\[x_{2} = \frac{- 5 - 11}{4} = - 4.\]