$$5x^3+x^2+3+x^3-6 = 0$$
Answer
$$ \begin{matrix}x_1 = 0.74185 & x_2 = -0.45426+0.68384i & x_3 = -0.45426-0.68384i \end{matrix} $$
Explanation
$$ \begin{aligned} 5x^3+x^2+3+x^3-6 &= 0&& \text{simplify left side} \\[1 em]6x^3+x^2-3 &= 0&& \\[1 em] \end{aligned} $$
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