We are given with,

A matrix of order 2 × 2, A = [a_ij].

We need to find the value of a₁₂.

Here, if A is of the order 2 × 2 then,

Number of rows of A = 2

Number of columns of A = 2

We can easily find the elements using the representation of element, .

Compare a_ij with a₁₂.

We get,

i = 1

j = 2

Putting these values in ,

Thus, the value of .