Question

A)= (A IJ) 2×2 EM QUE A IJ = 2 I+J , SE I≠J 1, SE I=J

Answer 1

$\Large\boxed{\begin{array}{l}\sf A=(a_{ij})_{2\times 2},a_{ij}=\begin{cases}\sf 2i+j,~~~se~~i\ne j\\\sf 1,~~se~~i=j\end{cases}\\\sf A=\begin{pmatrix}\sf a_{11}&\sf a_{12}\\\sf a_{21}&\sf a_{22}\end{pmatrix}\\\sf a_{11}=1\\\sf a_{12}=2\cdot1+2=2+2=4\\\sf a_{21}=2\cdot2+1=4+1=5\\\sf a_{22}=1\\\\\huge\sf A=\begin{pmatrix}\sf1&\sf4\\\sf5&\sf1\end{pmatrix}\end{array}}$