Chapter 5 - Linear Functions - 5-5 Standard Form - Practice and Problem-Solving Exercises - Page 324: 29

Please see the graph.

The line in question has multiple points on it. Some of these points include (1, -2), (2, -2), (0, -2), (-1, -2), and (-2, -2). All of these points have $y = -2$, so the line created by the points is a horizontal line.