The roots of polynomial $ p(x) $ are:
$$ \begin{aligned}x_1 &= 7.8911\\[1 em]x_2 &= 0.0545+1.0666i\\[1 em]x_3 &= 0.0545-1.0666i \end{aligned} $$Polynomial $ x^3-8x^2+2x-9 $ has no rational roots that can be found using Rational Root Test, so the roots were found using qubic formulas.