The roots of polynomial $ p(x) $ are:
$$ \begin{aligned}x_1 &= 6.3166\\[1 em]x_2 &= -0.3166 \end{aligned} $$The solutions of $ x^2-6x-2 = 0 $ are: $ x = 3-\sqrt{ 11 } ~ \text{and} ~ x = 3+\sqrt{ 11 }$.
You can use step-by-step quadratic equation solver to see a detailed explanation on how to solve this quadratic equation.