Explanation:
y = 6, if -2 <= x < 0
y = 5, if 0 <= x < 2
y = 4, if 2 <= x < 4
y = 3, if 4 <= x < 6
you have to look at the graph.
as we can see, every piece of line is horizontal and represents a constant value of y.
the top is y = 6.
then the next y = 5 and so on.
any horizontal line is represented by
y = n
n defines the y-value, where it intersects the y-axis.
therefore, the solution is as it is defined above.