Practice this lesson yourself on KhanAcademy.org right now: https://www.khanacademy.org/math/precalculus/precalc-matrices/matrix-equations/e/writing-systems-of-equations-as-matrix-equations?utm_source=YT&utm_medium=Desc&utm_campaign=Precalculus Watch the next lesson: https://www.khanacademy.org/math/precalculus/precalc-matrices/reduced_row_echelon/v/matrices-reduced-row-echelon-form-1?utm_source=YT&utm_medium=Desc&utm_campaign=Precalculus Missed the previous lesson? https://www.khanacademy.org/math/precalculus/precalc-matrices/matrix-equations/v/matrix-equations-systems?utm_source=YT&utm_medium=Desc&utm_campaign=Precalculus Precalculus on Khan Academy: You may think that precalculus is simply the course you take before calculus. You would be right, of course, but that definition doesn’t mean anything unless you have some knowledge of what…