$$x^4+\frac{2}{10}x^3+\frac{1}{100}x^2+\frac{4356}{100} = 0$$
Answer
$$ \begin{matrix}x_1 = 1.76693+1.81625i & x_2 = 1.76693-1.81625i & x_3 = -1.86693+1.81625i \\[1 em] x_4 = -1.86693-1.81625i & \\[1 em] \end{matrix} $$
Explanation
$$ \begin{aligned} x^4+\frac{2}{10}x^3+\frac{1}{100}x^2+\frac{4356}{100} &= 0&& \text{multiply ALL terms by } \color{blue}{ 100 }. \\[1 em]100x^4+100 \cdot \frac{2}{10}x^3+100\frac{1}{100}x^2+100\cdot\frac{4356}{100} &= 100\cdot0&& \text{cancel out the denominators} \\[1 em]100x^4+20x^3+x^2+4356 &= 0&& \\[1 em] \end{aligned} $$
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