When the sign is ≤ or ≥ (less/greater than or equal to), the dot is filled in.
When the sign is < or >, the dot is not filled in and looks like this o
To find out which number line represents the solution set, simplify the inequality and isolate x
Multiply -2 on both sides to get rid of -1/2
x ≤ -8 (The sign flips when you multiply/divide a negative number on both sides of the inequality)
so you get x is greater than or equal to -8, so you have a filled in circle on -8, and the arrow should be going to the right since x is greater than -8