Question

Sendo A=(aij)3x3, tal que Aij= 0 se i#J, 3.i-J se i=J.

Answer 1

$A= \left[\begin{array}{ccc}a11&aa12&a13\\a21&a22&a23\\a31&a32&a33\end{array}\right] = \left[\begin{array}{ccc}2&0&0\\0&4&0\\0&0&6\end{array}\right]$