Given \[{{a}_{i\text{ }j}}~=\text{ }i\]
Let \[A\text{ }=\text{ }{{[{{a}_{i\text{ }j}}]}_{4\times 3}}\]
So, the elements in a \[4\text{ }\times \text{ }3\] matrix are
\[{{a}_{11}},\text{}{{a}_{12}},\text{ }{{a}_{13}},\text{}{{a}_{21}},\text{}{{a}_{22}},\text{ }{{a}_{23}},\text{}{{a}_{31,}}{{a}_{32,}}{{a}_{33,}}{{a}_{41,}}{{a}_{42,}}{{a}_{43}}\]
\[A\text{ }=\]
\[{{a}_{11}}~=\text{ }1\]
\[{{a}_{12}}~=\text{ }1\]
\[{{a}_{13}}~=\text{ }1\]
\[{{a}_{21}}~=\text{ }2\]
\[{{a}_{22}}~=\text{ }2\]
\[{{a}_{23}}~=\text{ }2\]
\[{{a}_{31}}~=\text{ }3\]
\[{{a}_{32}}~=\text{ }3\]
\[{{a}_{33}}~=\text{ }3\]
\[{{a}_{41}}~=\text{ }4\]
\[{{a}_{42}}~=\text{ }4\]
\[{{a}_{43}}~=\text{ }4\]
Substituting these values in matrix A we get,
\[A\text{ }=\]
