TeX Quellcode:
\begin{array}{rclll}3\left(5b+1\right)-3b&=&21-2\left(4+\dfrac{5}{2}b\right)\cr\cr15b+3-3b&=&21-8-5b \cr 12b+3&=&-5b+13&\vert&+5b-3 \cr 17b&=&10&\vert&:17 \cr b&=&\dfrac{10}{17}\end{array}