What you must do for this case is to take all the numbers that satisfy the following inequality
x <= - 8
Notice that the inequality solution is
(-inf, -8]
In the graph the parenthesis implies that the value of minus infinity is not included. The bracket implies that the value x = -8 is included in the solution of the inequality.
See attached graph.
x <= - 8
Notice that the inequality solution is
(-inf, -8]
In the graph the parenthesis implies that the value of minus infinity is not included. The bracket implies that the value x = -8 is included in the solution of the inequality.
See attached graph.