TeX Quellcode:

{-\dfrac{1}{5}\left(-10s+11t\right)\left(10s-11t\right) = -\dfrac{1}{5}\left(-10s\cdot 10s-10s\cdot\left(-11t\right)+11t\cdot 10s+11t\cdot\left(-11t\right)\right) = -\dfrac{1}{5}\left(-100s^2+110st+110st-121t^2\right) = 20s^2-44st+\dfrac{121}{5}t^2}