The roots of polynomial $ p(x) $ are:
$$ \begin{aligned}x_1 &= 0.7302\\[1 em]x_2 &= -1.0787\\[1 em]x_3 &= 6.3485 \end{aligned} $$Polynomial $ x^3-6x^2-3x+5 $ has no rational roots that can be found using Rational Root Test, so the roots were found using qubic formulas.