TeX Quellcode:
\begin{array}{rclll} 8 &=& -\sqrt{x^3+28}+7 &\vert & -7 \cr 1 &=& -\sqrt{x^3+28} &\vert & ()^2 \cr 1 &=& x^3+28 &\vert & -28\cr -27 &=& x^3 &\vert & \sqrt[3]{ } \cr x &=& -3 \in\mathbb{D}\end{array}