Solve a simple absolute value equation (not stressed as much in the 5th edition as it was in the 4th edition). For a video explanation see https://www.khanacademy.org/math/algebra/solving-linear-equations-and-inequalities/absolute-value-equations/v/absolute-value-equations or http://patrickjmt.com/solving-absolute-value-equations-ex-1/ or http://patrickjmt.com/solving-absolute-value-equations-ex-2/