Who is asking: Student


Hi Erika, I drew a sketch of the line y = 2x + 1.Now consider some xcordinate, say x = a and look at all the points in the plane with xcordinate a. Some of these points are below the line, some are above the line and one is on the line. In my diagram the points in blue have x=a and are below the line, the points in orange have x=a and are above the line, and the red dot has x=a and is on the line. Since this red dot is on the line and its xcoordinate is a, its ycoordinate must be 2a+1. The blue points must then have ycoordinates less than 2a+1, that is the blue points satisfy y < 2x+1. Hence the part of the plane that satisfies y < 2x+1 is the region below the line y = 2x+1. Penny 

