Question

A= (a ij)4*3 em que 2,se i igual ou maior que j
-1 , sei < j

Answer 1

$A = (a ij)_ 4_x_3, tal que ===\ \textgreater \ a ij = \left \{ {{i \geq j=2} \atop {i\ \textless \ j=-1}} \right.$

$a__1_1 = 2$    $a__1_2 = -1$    $a__1_3 = -1$

$a__2_1 = 2$    $a__2_2 = 2$     $a__2_3= -1$

$a__3_1 = 2$    $a__3_2 = 2$     $a__3_3 = 2$

$a__4_1 = 2$    $a__4_2 = 2$     $a__4_3 = 2$


$A = \left[\begin{array}{cccc}2&-1&-1\\2&2&-1\\2&2&2\\2&2&2\end{array}\right]$