We next require taking a look at arithmetic involving matrices. We'll begin with addition and subtraction of two matrices. Therefore, assume that we have two n x m matrices, which is A and B. The sum or difference of these two matrices is after that,
A_{nxm }+ B_{nxm} = (a_{ij})_{nxm} + (b_{ij})_{nxm} = (a_{ij }+ b_{ij})_{nxm}
The difference or sum of two matrices of similar size is a new matrix of identical size that entries are the difference or sum of the consequent entries from the original two matrices. Remember that we can't subtract or add entries with different sizes.
Subsequently, let's look at scalar multiplication. Under scalar multiplication we are intended to multiply a matrix A with a constant it sometimes termed as a scalar a. Under this case we find a new matrix that entries have all been multiplied with the constant, a.
aA_{nxm} = a(a_{ij})_{nxm} = (aa_{ij})_{nxm}