The roots of polynomial $ p(x) $ are:
$$ \begin{aligned}x_1 &= -1.4732\\[1 em]x_2 &= -3.3164\\[1 em]x_3 &= -9.2104 \end{aligned} $$Polynomial $ x^3+14x^2+49x+45 $ has no rational roots that can be found using Rational Root Test, so the roots were found using qubic formulas.