TeX Quellcode:

\begin{array}{rcl} f_3(x_s) &=& f_3\left(-\dfrac{7}{10}\right) \cr &=&\dfrac{27}{9} \cdot \left(-\dfrac{7}{10} \right)+1 \cr &=&3\cdot\left(-\dfrac{7}{10} \right)+\dfrac{10}{10}\cr &=&-\dfrac{11}{10}\end{array}