The roots of polynomial $ p(x) $ are:
$$ \begin{aligned}x_1 &= 2.0563\\[1 em]x_2 &= 4.65\\[1 em]x_3 &= -4.7063 \end{aligned} $$Polynomial $ x^3-2x^2-22x+45 $ has no rational roots that can be found using Rational Root Test, so the roots were found using qubic formulas.