Arrays are important mathematical structures in organizing data into rows and columns. They are extremely important in solving linear systems and linear equations. Thus, matrices are a unique tool in other areas, such as: Engineering, Computing and other sciences. Between matrices we can perform calculations involving addition, subtraction and multiplication.
Let's demonstrate how to multiply a real number by an array of type mxn, where m represents the rows and n the columns. This type of multiplication is very simple, as it is enough to multiply the real number by all the elements belonging to the matrix. Watch: 
Let's perform some more multiplications in order to fix the methods used in this type of operation.
given the matrices 
and 
, determine:
a) 2A + 3B
b) 7A - 6B
by Mark Noah
Graduated in Mathematics
Brazil School Team
Matrix and Determinate - Math - Brazil School
Source: Brazil School - https://brasilescola.uol.com.br/matematica/multiplicando-um-numero-real-por-uma-matriz.htm