The roots of polynomial $ p(x) $ are:
$$ \begin{aligned}x_1 &= -0.1229+0.5172i\\[1 em]x_2 &= -0.1229-0.5172i\\[1 em]x_3 &= 1.1229+0.713i\\[1 em]x_4 &= 1.1229-0.713i \end{aligned} $$Polynomial $ 10x^4-20x^3+15x^2-2x+5 $ has no rational roots that can be found using Rational Root Test, so the roots were found using quartic formulas.