$\"\"$

For subtracing matrices, their dimension should be equal.

First write the dimension of the matrix.

The dimensions of matrix A and B are $\"\"$ .

The operation $\"\"$ is possible. $\"\"$

Multiply the matrix A by 4.

$\"\"$

$\"\"$ (Simplify) $\"\"$

Subtract the matrix $\"\"$ .

$\"\"$ (Substitute the values of 4A and B)

$\"\"$ (Subtract corresponding elements)

$\"\"$ (Simplify) $\"\"$

The value of $\"\"$ is $\"\"$ .