Question

A=(aij)2x3Tal Que aij= {i-j Se i=j}
{i+j se i≠j}

Answer 1

A = $\left[\begin{array}{ccc}a11&a12&a13\\a21&a22&a23\end{array}\right]$

aij= {i-j Se i=j}
a₁₁ = 1-1 = 0
a₂₂ = 2-2 = 0

aij= {i+j Se i≠j}
a₁₂ = 1+2 = 3
a₁₃ = 1+3 = 4
a₂₁ = 2+1 = 3
a₂₃ = 2+3 = 5

Logo, a matriz A será:
  A =  $\left[\begin{array}{ccc}0&3&4\\3&0&5\end{array}\right]$