TeX Quellcode:

\lambda_2\vec{a}=-2{,}5\begin{pmatrix}3\cr-4\end{pmatrix}=\begin{pmatrix}-2{,}5\cdot 3\cr-2{,}5\cdot \left(-4\right)\end{pmatrix}=\begin{pmatrix}-7{,}5\cr10\end{pmatrix}