TeX Quellcode:

\begin{array}{rclcl} -76(13+x)+87x^2 &=& 43x(-1+2x) \cr -988-76x+87x^2 &=& -43x+86x^2 & \vert & -86x^2+43x \cr x^2-33x-988 &=& 0 \cr x_{1,2} &=& \dfrac{33}{2} \pm \sqrt{\dfrac{1.089}{4}+988} \cr\cr x_1 &=& \dfrac{33}{2}+\dfrac{71}{2} = 52 \cr\cr x_2 &=& \dfrac{33}{2}-\dfrac{71}{2} = -19 \cr \cr \mathbb{L} &=& \{-19; 52\} \end{array}