TeX Quellcode:

\begin{array}{rclll} f(x) &=& 80x^2-16x+23 \cr\cr f \left(\dfrac{1}{10}\right) &=& 80\cdot \left(\dfrac{1}{10}\right)^2-16\cdot \dfrac{1}{10}+23 &=& \dfrac{111}{5} \end{array}