3x² -16x-12 =0
We can solve this equation using formula.
a=3, b=-16, c=-12
[tex]x= \frac{-b+/- \sqrt{b^{2} -4ac} }{2a}
\\ \\ x= \frac{16+/- \sqrt{16^{2}+4*3*12} }{2*3} = \frac{16+/- \sqrt{400} }{6} = \frac{16+/-20}{6}
\\ \\ x_{1}= \frac{16+20}{6} =6
\\ \\x_{2}= \frac{16-20}{6} =- \frac{4}{6} = -\frac{2}{3} [/tex]