Ej 1 de Ecuaciones Matriciales

Dadas las matrices:

$A = \left( \begin{array}{cc} 1 & 2 \\ 2 & 4 \end{array} \right)$ $\qquad$ $B = \left( \begin{array}{cc} 2 & 0 \\ 0 & 4 \end{array} \right)$ $\qquad$ $C = \left( \begin{array}{cc} 2 & 0 \\ 0 & 4 \end{array} \right)$