Answer:
The line going to the left aka the negative side!
X < -15 means X is less than -15
The line's purpose is to to show the possibilities of X.
So all the numbers lower than -15 are all possibilities of X. (Example: -16, -17 or -20 would be a possibilty of X because they are less than -15!)
Anything going above -15 is not a possibility of X (Example: -14, -13, or 2 are not possibilities of X as they are greater than -15!)
