Perpendicular and Parallel Lines-Section 2.7-2.8
Given an equation and a point, find the equation of the line that is perpendicular or parallel that goes through the given point.
For a video explanation, see
https://www.khanacademy.org/math/algebra/linear-equations-and-inequalitie/more-analytic-geometry/v/equations-of-parallel-and-perpendicular-lines