Question
$$x^4-13x^2+36 = 20$$
Answer
This equation has no solution.
Explanation
$$ \begin{aligned} x^4-13x^2+36 &= 20&& \text{move all terms to the left hand side } \\[1 em]x^4-13x^2+36-20 &= 0&& \text{simplify left side} \\[1 em]x^4-13x^2+16 &= 0&& \\[1 em] \end{aligned} $$
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