TeX Quellcode:

\begin{array}{rclcll}\sqrt{9x^2-42x+49}+3x &=& 7 &\vert & -3x \\\sqrt{9x^2-42x+49} &=& -3x+7 &\vert & ()^2 \\9x^2-42x+49 &=& 9x^2-42x+49 &\vert& -9x^2+42x-49 \\0 &=& 0 \end{array}