Solución al ejercicio 7074

- A^{-1}=\left( \begin{array}{cc} 1 & -2 \\ 0 & 1 \end{array} \right) - B^{-1}=\left( \begin{array}{ccc} \frac{1}{3} & 0 & 0 \\ 0 & 1 & 0 \\ 0 & 0 & 1 \end{array} \right) - C=\left( \begin{array}{cccc} 1 & 0 & 0 & 0 \\ 0 & 1 & 0 & 0 \\ 0 & 0 & 0 & 1 \\ 0 & 0 & 1 & 0 \end{array} \right)