TeX Quellcode:

\begin{array}{rclcl}(2x+3)^2-13 & \geq & (x-5)(x+5)+3x(x-3) \\4x^2+12x+9-13 & \geq & x^2-25+3x^2-9x \\ 4x^2+12x-4 & \geq & 4x^2-9x-25 & \vert & -4x^2 +9x +4 \\ 21x & \geq & -21 & \vert & :21 \\ x & \geq & -1\end{array}