Can someone plz explain to me when to use an open and closed dot

closed dot is if the number is part of the solution so if it is equal to

 and

use open if it is not part of solution as in if it is greater than or less than

 so for your picture x greater or equal to -2 it would be a closed dot

the circle one

the answer is d

the answer is in the first quadrant, which make the y-int positive.

since the dots are going down, therefore the correlation is negative

i hope it is right.