Refer to the image below for the graph.
Work Step by Step
RECALL: The graph of the equation $y=k$ is a horizontal line. Every point on the line has the same y-value. Thus, to graph $y=0$, you can plot the points (-3, 0), (3, 0), and (3, 0), and then you can connect them using a line. (Refer to the image in the answer part above.)