The roots of polynomial $ p(x) $ are:
$$ \begin{aligned}x_1 &= 3.2732\\[1 em]x_2 &= 0.9265+0.7078i\\[1 em]x_3 &= 0.9265-0.7078i\\[1 em]x_4 &= -0.5631+1.0155i\\[1 em]x_5 &= -0.5631-1.0155i \end{aligned} $$Polynomial $ x^5-4x^4+3x^3-3x^2+5x-6 $ has no rational roots that can be found using Rational Root Test, so the roots were found using Newton method.