TeX source:
\begin{array}{rclcl} 3.125x^5+1 &=& 0 &\vert & -1 \cr\cr 3.125x^5 &=& -1 &\vert & :3.125 \cr\cr x^5 &=& -\dfrac{1}{3.125} &\vert& \sqrt[5]{} \cr\cr x_1 &=& \sqrt[5]{-\dfrac{1}{3.125}} \cr\cr x_1 &=& -\sqrt[5]{\left\vert -\dfrac{1}{3.125}\right\vert} \cr\cr x_1 &=& -\dfrac{1}{5} \cr\cr \mathbb{L} &=& \left\{-\dfrac{1}{5}\right\} \end{array}