Explanation:
the domain of a function is the interval or set of all valid x (input) values.
the range of a function is the interval or set of all valid y (function result) values.
we see in the graph that we get for y all continuous values between 0 (max) and -9 (min).
both end points are filled, so we need to include them into the interval of valid values (via the <= or >= signs).
so the range is
-9 <= y <= 0