The roots of polynomial $ p(x) $ are:
$$ \begin{aligned}x_1 &= 0.9065\\[1 em]x_2 &= 2.3186\\[1 em]x_3 &= -15.2251 \end{aligned} $$Polynomial $ x^3+12x^2-47x+32 $ has no rational roots that can be found using Rational Root Test, so the roots were found using qubic formulas.