$\"\"$

For subtracting matrices, their dimension should be equal.

First write the dimension of the matrix.

The dimensions of matrices D and C are $\"\"$ .

The operation $\"\"$ is possible.

$\"\"$

Multiply the matrix C by 2.

$\"\"$

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

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

Perform the operation $\"\"$ .

$\"\"$ (Substitute the values of D and 2C)

$\"\"$ (Subtract corresponding elements)

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

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