$$-5000+10000x+30000x^2-40000x^3 = 0$$
Answer
$$ \begin{matrix}x_1 = 0.32229 & x_2 = -0.44461 & x_3 = 0.87232 \end{matrix} $$
Explanation
$$ \begin{aligned} -5000+10000x+30000x^2-40000x^3 &= 0&& \text{simplify left side} \\[1 em]-40000x^3+30000x^2+10000x-5000 &= 0&& \\[1 em] \end{aligned} $$
This polynomial has no rational roots that can be found using Rational Root Test.
Roots were found using qubic formulas.
This page was created using
Polynomial Equations Solver