\[12m² + m - 6 = 0\ \]
\[a = 12,\ \ b = 1,\ \ c = - 6\]
\[D = b^{2} - 4ac =\]
\[= 1^{2} - 4 \cdot 12 \cdot ( - 6) =\]
\[= 1 + 288 = 289\]
\[m_{1,2} = \frac{- b \pm \sqrt{D}}{2a}\]
\[m_{1} = \frac{- 1 + \sqrt{289}}{2 \cdot 12} = \frac{- 1 + 17}{12} =\]
\[= \frac{16}{24} = \frac{2}{3}\]
\[m_{2} = \frac{- 1 - \sqrt{289}}{2 \cdot 12} = \frac{- 1 - 17}{12} =\]
\[= - \frac{18}{12} = - \frac{3}{4}\]
\[Ответ:m = \frac{2}{3};m = - \frac{3}{4}.\]