Fundamentals of Statistics contains material of various lectures and courses of H. Lohninger on statistics, data analysis and here for more.

Matrix Addition and Subtraction

Adding or subtracting matrices is simple and can be accomplished by adding/subtracting the corresponding matrix elements:

crs := ars + brs,

with C, A, and B being the respective matrices. The order of the matrices A and B must be the same. Matrices of unequal order cannot be added or subtracted.

The zero matrix 0 naturally arises from subtracting two identical matrices and contains only zero elements.

A - A = 0

Let's take a look at an example: