TeX source:
\begin{array}{rclcl} 2u^2 -16u+30 &=& 0 &\vert& :2 \cr u^2-8u+15 &=& 0 &\vert& \text{p-q-Formel} \cr u_{1,2} &=& 4\pm \sqrt{16-15} \cr u_{1,2} &=& 4\pm \sqrt{1}\cr\cr u_1 &=& 4+1 = 5 \cr u_2 &=& 4-1 = 3\end{array}