TeX Quellcode:

\begin{array}{rclll} 9x^2-42x+49 &=& 0 &\vert & :9\\x^2-\dfrac{14}{3}x+\dfrac{49}{9} &=& 0 &\vert & \text{p-q-Formel}\\x_{1,2} &=& \dfrac{7}{3}\pm\sqrt{\left(-\dfrac{7}{3}\right)^2-\dfrac{49}{9}}\\x_{1,2} &=& \dfrac{7}{3}\pm 0\end{array}