The roots of polynomial $ p(x) $ are:
$$ \begin{aligned}x_1 &= 0.4131\\[1 em]x_2 &= 3.5214\\[1 em]x_3 &= 0.0328+0.8285i\\[1 em]x_4 &= 0.0328-0.8285i \end{aligned} $$Polynomial $ 5x^4-20x^3+12x^2-14x+5 $ has no rational roots that can be found using Rational Root Test, so the roots were found using quartic formulas.