TeX Quellcode:
\begin{array}{rcl} \dfrac{1}{2}[6(12+4ab)\cdot3c-b(10a+20c)]+19 &=&\dfrac{1}{2}[(6\cdot12+6\cdot4ab)\cdot3c-10ab-20bc]+19 \cr\cr &=&\dfrac{1}{2}[(72+24ab)\cdot3c-10ab-20bc]+19 \cr\cr &=&\dfrac{1}{2}[72\cdot3c+24ab\cdot3c-10ab-20bc]+19 \cr\cr &=&\dfrac{1}{2}[216c+72abc-10ab-20bc]+19 \cr\cr &=&\dfrac{1}{2}\cdot216c+\dfrac{1}{2}\cdot72abc+\dfrac{1}{2}\cdot(-10ab)+\dfrac{1}{2}\cdot(-20bc)+19 \cr\cr &=&36abc-5ab-10bc+108c+19 \end{array}