$$x^4+2x^3+x^2-x+10 = x+4$$
Answer
$$ \begin{matrix}x_1 = 0.7123+0.89846i & x_2 = 0.7123-0.89846i & x_3 = -1.7123+1.27754i \\[1 em] x_4 = -1.7123-1.27754i & \\[1 em] \end{matrix} $$
Explanation
$$ \begin{aligned} x^4+2x^3+x^2-x+10 &= x+4&& \text{move all terms to the left hand side } \\[1 em]x^4+2x^3+x^2-x+10-x-4 &= 0&& \text{simplify left side} \\[1 em]x^4+2x^3+x^2-2x+6 &= 0&& \\[1 em] \end{aligned} $$
This polynomial has no rational roots that can be found using Rational Root Test.
Roots were found using quartic formulas
This page was created using
Polynomial Equations Solver