Ejercicio 4 (J-2005-1 UNED)

Dadas las matrices
$A = \left( \begin{array}{cc} 2 & 2 \\ 1 & 3 \end{array} \right) \qquad B = \left( \begin{array}{cc} 2 & 5 \\ 2 & -1 \end{array} \right)$
calcula