Answer as an inequality is -7 ≤ x ≤ 3
Answer in interval notation [-7, 3]
Explanation
The domain is the set of allowed x inputs. The smallest x can get is x = -7 which is at the left-most part of the curve. The largest is x = 3. We include both endpoints due to closed endpoints (i.e. there aren't any open holes). Square brackets are used to include endpoints for interval notation.
In words the domain can be described as "x is any number between -7 and 3 including both endpoints".
