A closed circle means inclusive, and -2 is included in values that would make the equation true. Then you just have to test another number greater than and less than -2 to see which way the arrow should point.
-3(-3) + 1 < 7
9 + 1 < 7
10 < 7 FALSE
-3(0) + 1 < 7
1 < 7 TRUE
All values (including -2) will make this equation true
