TeX source:
\begin{array}{crclll} & -7 &=& 5x^{13}-7x^9-7 & \vert & +7 \cr & 0 &=& 5x^{13}-7x^9 \cr & 0 &=& x^9\left(5x^4-7\right) & \vert & \text{Satz vom Nullprodukt} \cr \text{Faktor 1:} & x^9 &=& 0 &\vert& \sqrt[9]{} \cr & x_2 &=& 0 & & \rightarrow \quad P_2(0 \mid -7) \cr\cr \text{Faktor 2:} & 5x^4-7 &=& 0 & \vert & +7 \cr & 5x^4 &=& 7 & \vert & :5 \cr & x^4 &=& \dfrac{7}{5} & \vert & \pm\sqrt[4]{} \cr & x_3 &=& \sqrt[4]{\dfrac{7}{5}} & & \rightarrow \quad P_3\left(\sqrt[4]{\dfrac{7}{5}} \mid -7\right) \cr & x_4 &=& -\sqrt[4]{\dfrac{7}{5}} & & \rightarrow \quad P_4\left(-\sqrt[4]{\dfrac{7}{5}} \mid -7\right) \end{array}