The roots of polynomial $ p(x) $ are:
$$ \begin{aligned}x_1 &= 0.4131\\[1 em]x_2 &= 1.4119\\[1 em]x_3 &= -0.3125+0.8716i\\[1 em]x_4 &= -0.3125-0.8716i \end{aligned} $$Polynomial $ 10x^4-12x^3+3x^2-12x+5 $ has no rational roots that can be found using Rational Root Test, so the roots were found using quartic formulas.