The roots of polynomial $ p(x) $ are:
$$ \begin{aligned}x_1 &= 21.5901\\[1 em]x_2 &= 81.2874\\[1 em]x_3 &= -92.8775 \end{aligned} $$Polynomial $ x^3-10x^2-7800x+163000 $ has no rational roots that can be found using Rational Root Test, so the roots were found using qubic formulas.