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

Elimination method review (systems of linear equations)(https://www.khanacademy.org/math/algebra/systems-of-linear-equations/equivalent-systems-of-equations/a/elimination-method-review)

Substitution method review (systems of equations)(https://www.khanacademy.org/math/algebra/systems-of-linear-equations/solving-systems-of-equations-with-substitution/a/substitution-method-review-systems-of-equations)

Solving linear systems with matrices(https://www.khanacademy.org/math/precalculus/precalc-matrices/row-echelon-and-gaussian-elimination/v/matrices-reduced-row-echelon-form-2)