$\"\"$

For subtracting matrices, their dimension should be equal.

First write the dimension of the matrix.

The dimensions of matrix are $\"\"$ .

The operation is possible.

$\"\"$

Multiply the matrix by 8.

$\"\"$

$\"\"$ (Multiply each element by 8)

$\"\"$ (Simplify)

$\"\"$

Multiply the matrix by -2.

$\"\"$

$\"\"$ (Multiply each element by-2)

$\"\"$ (Simplify)

$\"\"$

Perform the operation

$\"\"$

$\"\"$ (Subtract corresponding elements)

$\"\"$ (Simplify)

$\"\"$

The value is $\"\"$ .