The roots of polynomial $ p(x) $ are:
$$ \begin{aligned}x_1 &= -0.3208\\[1 em]x_2 &= -1.6902\\[1 em]x_3 &= 1.8443 \end{aligned} $$Polynomial $ 6x^3+x^2-19x-6 $ has no rational roots that can be found using Rational Root Test, so the roots were found using qubic formulas.