\[\ 3x² + 8x - 3 = 0\]
\[D = b^{2} - 4ac = 64 - 4 \cdot 3 \cdot ( - 3) =\]
\[= 64 + 36 = 100\]
\[x_{1} = \frac{- 8 + 10}{6} = \frac{2}{6} = \frac{1}{3}\]
\[x_{2} = \frac{- 8 - 10}{6} = - \frac{18}{6} = - 3\]
\[Ответ:x = \frac{1}{3}\ \ и\ \ x = - 3.\]