Solving Linear Systems: Elementary Matrices
http://www.maa.org/taxonomy/term/42334/0
enA Short Proof of the Two-sidedness of Matrix Inverses
http://www.maa.org/programs/faculty-and-departments/classroom-capsules-and-notes/a-short-proof-of-the-two-sidedness-of-matrix-inverses
<div class="field field-name-body field-type-text-with-summary field-label-hidden"><div class="field-items"><div class="field-item even"><p><em>The paper gives a short proof that for any \(n\) x \(n\) matrices \(A\) and \(C\) over a field of scalars, \(AC = I\) if and only if \(CA = I\).</em> <em>The proof relies on familiarity with elementary matrices and the reduced row echelon form.</em></p>
</div></div></div>Classroom Capsules and Notes for Solving Linear Systems: Elementary Matrices in Linear Algebra
http://www.maa.org/programs/faculty-and-departments/course-communities/classroom-capsules-and-notes-for-solving-linear-systems-elementary-matrices-in-linear-algebra