Using quadratic formula:
[tex]\begin{gathered} x=\frac{-b\pm\sqrt[]{b^2-4ac}}{2a} \\ x=\frac{-12\pm\sqrt[]{144-4(1)(23)}}{2} \\ x=\frac{-12\pm\sqrt[]{52}}{2} \\ x=-6\pm\sqrt[]{13} \end{gathered}[/tex]Therefore, the solutions are:
[tex]\begin{gathered} x=\sqrt[]{13}-6 \\ or \\ x=-\sqrt[]{13}-6 \end{gathered}[/tex]