STANDARD A.REI.D.10
AI

Understand that the graph of an equation in two variables is the set of all its solutions plotted in the coordinate plane.  Graphing linear equations is a fluency recommendation.  Students become fluent in solving characteristic problems involving the analytic geometry of lines, such as writing down the equation of a line given a point and a slope. Such fluency can support them in solving less routine mathematical problems involving linearity; as well as modeling linear phenomena.