Question

Determine a matriz x tal que X-3B= $I_{3}$, dado que:

$b \left[\begin{array}{ccc}1&5&0\\-1&-2&3\\7&0&2\end{array}\right] }$

Answer 1

$X=\left[\begin{matrix}1&0&0\\0&1&0\\0&0&1\end{matrix}\right]+3\left[\begin{matrix}1&5&0\\-1&-2&3\\7&0&2\end{matrix}\right]=\left[\begin{matrix}4&15&0\\-3&-5&9\\21&0&7\end{matrix}\right]$