TeX Quellcode:

\begin{array}{rclcl} \mathbb{D} &=& \mathbb{R} \cr \cr 2(x+5)^2-(x-4)(x+5) &=& (x-4)^2 \cr 2x^2+20x+50-x^2-x+20 &=& x^2-8x+16 \cr x^2+19x+70 &=& x^2-8x+16 &\vert& -x^2+8x-70 \cr 27x &=& -54 &\vert& :27 \cr x &=& -2 \cr \cr \mathbb{L} &=& \{-2\} \end{array}