Answer:
1) D
2) C
3) D
4) B
Explanation:
Background info: Left pointing vector is less than, right pointing is greater than. A circle without the middle filled in shows that value is excluded, a full circle shows included(which would be greater than or equal to, and less than or equal to)
With that you look at the sign for each problem and apply what I wrote above.
For example for question 1, x is greater than or equal to 8 so you pick the right/positive arrow, and the filled in circle.
Hope this helps!