The roots of polynomial $ p(x) $ are:
$$ \begin{aligned}x_1 &= 0.5516\\[1 em]x_2 &= 2.7631\\[1 em]x_3 &= -0.0574+0.808i\\[1 em]x_4 &= -0.0574-0.808i \end{aligned} $$Polynomial $ 5x^4-16x^3+9x^2-10x+5 $ has no rational roots that can be found using Rational Root Test, so the roots were found using quartic formulas.