The roots of polynomial $ p(x) $ are:
$$ \begin{aligned}x_1 &= -1.5037\\[1 em]x_2 &= 4.112\\[1 em]x_3 &= 0.1958+0.3513i\\[1 em]x_4 &= 0.1958-0.3513i \end{aligned} $$Polynomial $ x^4-3x^3-5x^2+2x-1 $ has no rational roots that can be found using Rational Root Test, so the roots were found using quartic formulas.