- TeX source:
- \begin{array}{rclcl} 0 &=& -12x^2+12x+240 &\vert& \text{a-b-c-Formel} \cr x_{2,3} &=& \dfrac{-12\pm\sqrt{12^2-4\cdot(-12)\cdot 240}}{2\cdot(-12)} \cr\cr x_{2,3} &=& \dfrac{-12\pm\sqrt{11.664}}{-24} \cr\cr x_2 &=& \dfrac{-12+108}{-24} = -4 \cr\cr x_3 &=& \dfrac{-12-108}{-24} = 5 \cr\cr \mathbb{L} &=& \{-4;1;5\} \end{array}