Resposta:
[tex]A^{2} +3A=\left[\begin{array}{ccc}30&20\\10&20\end{array}\right][/tex]
Explicação passo-a-passo:
[tex]A^{2} =\left[\begin{array}{ccc}4&2\\1&3\end{array}\right] *\left[\begin{array}{ccc}4&2\\1&3\end{array}\right] =\left[\begin{array}{ccc}4*4+2*1&4*2+2*3\\1*4+3*1&1*2+3*3\end{array}\right] \\A^{2} =\left[\begin{array}{ccc}18&14\\7&11\end{array}\right] \\\\3A=3*\left[\begin{array}{ccc}4&2\\1&3\end{array}\right] \\\\3A=\left[\begin{array}{ccc}12&6\\3&9\end{array}\right] \\\\\\A^{2} +3A=\left[\begin{array}{ccc}30&20\\10&20\end{array}\right][/tex]
