Question

Sendo A²= [1 2] calcule: 3A – A + I2
3 4​

Answer 1

$A_2=\left[\begin{array}{cc}1&2\\3&4\\ \end{array}\right]$

calcular 3A-A+l2

$3.\left[\begin{array}{cc}1&2\\3&4\\ \end{array}\right] -\left[\begin{array}{cc}1&2\\3&4\\ \end{array}\right] +\left[\begin{array}{cc}0&0\\3&4\\ \end{array}\right]=\left[\begin{array}{cc}3&6\\9&12\\ \end{array}\right]-\left[\begin{array}{cc}1&2\\3&4\\ \end{array}\right] +\left[\begin{array}{cc}0&0\\3&4\\ \end{array}\right] =\\\\\left[\begin{array}{cc}3&6\\9&12\\ \end{array}\right]-\left[\begin{array}{cc}1&2\\6&8\\ \end{array}\right] =\left[\begin{array}{cc}2&4\\3&4\\ \end{array}\right]$