Question

How do I solve this ?

Answer 1

$\left[\begin{array}{cc}3&6\\-1&-3\\-5&-1\end{array}\right] + \left[\begin{array}{cc}0&-1\\6&0\\2&3\end{array}\right] = \left[\begin{array}{cc}3+0&6-1\\-1+6&-3+0\\-5+2&-1+3\end{array}\right] = \left[\begin{array}{cc}3&5\\5&-3\\-3&2\end{array}\right]$

$-5\left[\begin{array}{ccc}5&6&-4\\4&-2&-1\end{array}\right] =\left[\begin{array}{ccc}-5(5)&-5(6)&-5(-4)\\-5(4)&-5(-2)&-5(-1)\end{array}\right]\\=\left[\begin{array}{ccc}-25&-30&20\\-20&10&5\end{array}\right]$