TeX source:
\begin{array}{crclcl} & x^2+x &=& 6\sqrt{10}x &\vert& -6\sqrt{10}x \cr & x^2-6\sqrt{10}x+x &=& 0 \cr & x(x-6\sqrt{10}+1) &=& 0 \cr \text{Faktor 1:} & x_1 &=& 0 \cr\cr \text{Faktor 2:} & x_2-6\sqrt{10}+1 &=& 0 \cr & x_2 &=& 6\sqrt{10}-1 \cr\cr & \mathbb{L} &=& \left\{0; 6\sqrt{10}-1\right\} \end{array}