About Lesson
Elementary Linear Algebra: Applications Version, 11th Edition (http://bcs.wiley.com/he-bcs/Books?action=index&itemId=1118434412&bcsId=8466)
Matrix row operations (https://www.khanacademy.org/math/precalculus/precalc-matrices/elementary-matrix-row-operations/e/perform-elementary-matrix-row-operations)
Intro to matrix inverses (https://www.khanacademy.org/math/precalculus/precalc-matrices/intro-to-matrix-inverses/v/inverse-matrix-part-1)