TeX Quellcode:

\begin{array}{rcl}f\left(x_1\right) &=& f\left(0\right) \cr&=& -0 + 4 \cr &=& 4 \cr\cr f\left(x_2\right) &=& f\left(5{,}5\right) \cr&=& -5{,}5+ 4 \cr &=& -1{,}5 \end{array}