Question

A= [aij] 2×2 , tal que aij= (i + j)2 -1.

Answer 1

Olá!

Vamos construir uma Matriz $A_{2x2} = \left[\begin{array}{cc}a_{11}&a_{12}\\a_{21}&a_{22}\end{array}\right]$ sendo que: 

$a_{ij}= (i + j)*2 -1$

$a_{11} = (1+1)*2-1=(2)*2-1=4-1=\boxed{3}$
$a_{12} = (1+2)*2-1=(3)*2-1=6-1=\boxed{5}$
$a_{21} = (2+1)*2-1=(3)*2-1=6-1=\boxed{5}$
$a_{22} = (2+2)*2-1=(4)*2-1=8-1=\boxed{7}$

Então:

$A = \left[\begin{array}{cc}3}&5\\5&7\end{array}\right] \end{array}}\qquad\quad\checkmark$