Exercise 20 Page 260

Graphing a single inequality involves two main steps.

1. Plotting the boundary line.
2. Shading half of the plane to show the solution set.

Here, we need to do this process for each of the inequalities in the system. The system's solution set will be the intersection of the shaded regions in the graphs of (I), (III), and (III).

Boundary Lines

We can tell a lot of information about the boundary lines from the inequalities given in the system.