$\"\"$

The operation of the matrix expression is $\"\"$ .

Multiplication of two matrices possible if the number of columns in the first matrix equals the number of rows in the second matrix.

The dimensions of the matrix $\"\"$ are $\"\"$ and the number of columns in the matrix is $\"\"$ .

The dimensions of the matrix $\"\"$ are $\"\"$ and the number of the rows in the matrix is $\"\"$ .

The number of columns in the matrix $\"\"$ is not equals the number of rows in the matrix $\"\"$ .

Thus, matrix product $\"\"$ is impossible.

$\"\"$

The matrix product $\"\"$ is undefined and matrix $\"\"$ is impossible.