The roots of polynomial $ p(x) $ are:
$$ \begin{aligned}x_1 &= 0.4098\\[1 em]x_2 &= -0.8906\\[1 em]x_3 &= 5.4808 \end{aligned} $$Polynomial $ -2x^3+10x^2+6x-4 $ has no rational roots that can be found using Rational Root Test, so the roots were found using qubic formulas.