The roots of polynomial $ p(x) $ are:
$$ \begin{aligned}x_1 &= 0.6608\\[1 em]x_2 &= -2.3304+1.9103i\\[1 em]x_3 &= -2.3304-1.9103i \end{aligned} $$Polynomial $ x^3+4x^2+6x-6 $ has no rational roots that can be found using Rational Root Test, so the roots were found using qubic formulas.