**In the Cartesian Plane, the slope of a graph represents the rate of change of the graph.** The slope of graph at any given point is the point's "y" value (rise) divided by the "x" value (run).

The slope of a graph illustrates the rate of change from one point on the graph to another point. It may be either positively sloped, sloping upward from left to right, or negatively sloped, sloping downward from left to right. Steeper graphs have a greater rate of change than do shallower graphs. A perfectly vertical graph has an undefined slope, while a perfectly horizontal graph has a slope of zero.