TeX Quellcode:

\begin{array}{rclcc} x^2-3x-4 &=& 0 \cr x_{1,2} &=& -\dfrac{-3}{2} \pm \sqrt{\left(\dfrac{-3}{2} \right)^2-\left(-4\right)} \cr\cr x_{1,2} &=& \dfrac{3}{2} \pm \sqrt{\dfrac{9}{4}+4} \cr\cr x_{1,2} &=& \dfrac{3}{2} \pm \sqrt{\dfrac{9+16}{4}} \cr\cr x_{1,2} &=& \dfrac{3}{2} \pm \sqrt{\dfrac{25}{4}} \cr\cr x_{1,2} &=& \dfrac{3}{2} \pm \dfrac{5}{2} \cr\cr\cr x_1 &=& \dfrac{3}{2}+\dfrac{5}{2} = \dfrac{8}{2} = 4 \cr\cr x_2 &=& \dfrac{3}{2} -\dfrac{5}{2} = -\dfrac{2}{2} = -1 \cr \cr \mathbb{L} &=& \{-1;4\} \end{array}