Elementary Linear Algebra: Applications Version, 11th Edition (http://bcs.wiley.com/he-bcs/Books?action=index&itemId=1118434412&bcsId=8466)

Intro to matrices (https://www.khanacademy.org/math/precalculus/precalc-matrices/intro-to-matrices/v/introduction-to-the-matrix)

Adding & subtracting matrices (https://www.khanacademy.org/math/precalculus/precalc-matrices/adding-and-subtracting-matrices/v/matrix-addition-and-subtraction-1)

Multiplying matrices(https://www.khanacademy.org/math/precalculus/precalc-matrices/multiplying-matrices-by-matrices/v/multiplying-a-matrix-by-a-matrix)