Posted by MATH DUDE on .
Explain how to know wheather the endpoint of the graph of an inequality should be a closed dot or an open dot.

MATH PREALGEBRA 
Jen,
It should be an open dot because it's an inequality. It would be a closed dot if it was an equality, such as x=3.

MATH PREALGEBRA 
Reiny,
If the inequality contains either ≤ or ≥, then close the dot of the endpoint, since that point is included in the graph.
If the inequality contains eitehr < or > , then leave the dot open to show that the endpoint itself is not included in your graph. 
MATH PREALGEBRA 
kim,
yes! if it is addition or subtraction you have an open dot! if it multiplication or division than a closed dot!