The roots of polynomial $ p(x) $ are:
$$ \begin{aligned}x_1 &= 14.0351\\[1 em]x_2 &= -1.0175+1.5897i\\[1 em]x_3 &= -1.0175-1.5897i \end{aligned} $$Polynomial $ x^3-12x^2-25x-50 $ has no rational roots that can be found using Rational Root Test, so the roots were found using qubic formulas.