The roots of polynomial $ p(x) $ are:
$$ \begin{aligned}x_1 &= 1.8834\\[1 em]x_2 &= -0.9417+5.0656i\\[1 em]x_3 &= -0.9417-5.0656i \end{aligned} $$Step 1:
Combine like terms:
$$ x^3 \color{blue}{-2x} + \color{blue}{25x} -50 = x^3+ \color{blue}{23x} -50 $$Step 2:
Polynomial $ x^3+23x-50 $ has no rational roots that can be found using Rational Root Test, so the roots were found using qubic formulas.