Let A be any matrix. Let k be any non-zero scalar. The matrix kA is obtained by multiplying all the entries of matrix A by the non-zero scalar k.
A = [aij]m×n
⇒ kA = [kaij]m×n
This is called scalar multiplication of a matrix.
If a matrix A is of order m×n, then the matrix kA is also of the same order m×n.