TeX source:
\begin{array}{crclcl} & \mathbb{D} &=& \mathbb{R} \cr\cr & 0 &=& 123(x+13)10^{2x+5} &\vert& \text{Satz vom Nullprodukt} \cr \text{Faktor 1:} & 0 &=& 123(x+13) &\vert& :123 \cr & 0 &=& x+13 &\vert& -13 \cr & -13 &=& x \cr\cr \text{Faktor 2:} & 0 &=& 10^{2x+5} \end{array}