TeX Quellcode:

\begin{array}{rclcl} -4z^2+28z+15 &=& 0 &\vert & :(-4) \cr z^2-7z-\dfrac{15}{4} &=& 0 &\vert & \text{p-q-Formel} \cr z_{1,2} &=& \dfrac{7}{2}\pm\sqrt{\left(-\dfrac{7}{2}\right)^2+\dfrac{15}{4}} \cr z_{1,2} &=& \dfrac{7}{2}\pm\sqrt{16} \cr\cr z_1 &=& \dfrac{7}{2}+4 = \dfrac{15}{2} \cr\cr z_2 &=& \dfrac{7}{2}- 4 = -\dfrac{1}{2} \end{array}