The quadratic formula is [tex]x=\frac{-b\pm\sqrt{b^2-4ac} }{2a}[/tex].
From the problem, a is 1, b is -1, and c is 12. Plugging in these values gives:
[tex]x=\frac{-(-1(-1)\pm\sqrt{(-1)^2-4(1)(12)} }{2(1)}[/tex]
Because there is a square root of a negative number, there is no solution.