TeX Quellcode:

\begin{array}{rclll}\dfrac{x+7-x^2}{x^4+1} &=& 0 &\vert& \cdot\left(x^4+1\right) \cr -x^2+x+7 &=& 0 &\vert& \text{a-b-c-Formel} \cr x_{1,2} &=& \dfrac{-1\pm\sqrt{1+28}}{-2} \cr\cr x_{1} &=& \dfrac{1+\sqrt{29}}{2} \approx 3{,}19 \in\mathbb{D} \cr x_{2} &=& \dfrac{1-\sqrt{29}}{2} \approx -2{,}19 \in\mathbb{D} \end{array}