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A=[1 2 3 4];
B=[5 6 7 8];
A+B
produces

ans =
681012

If we had subtraction of two matrices, it would be the same syntax as above
but using the minus sign between the matrices.

8.3 Multiplying a Matrix by a Scalar
If we multiply a matrix by a number, each element of the matrix is multiplied
by that number.

Entering:

3*A

produces

ans =
36912
Entering:

3*(A+B)

produces

ans =
18 24 30 36

8.4 Multiplying Matrices

Two matrices A(m ⊗ n) and B(r ⊗ s) can be multiplied only if n = r. The size
of the product matrix is (m ⊗ s). An element of the product matrix is obtained
from those of the constitutent matrices through the following rule:

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