Pearson Algebra 1 Common Core, 2011
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Pearson Algebra 1 Common Core, 2011 View details
1. Inequalities and Their Graphs
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Exercise 23 Page 168

For inequalities on a number line, what does it mean when a point is open or closed?

Practice makes perfect
To graph an inequality on a number line, we need to make note of two things: the direction of the inequality and whether it is strict.

z ≤ -5 Observing the given inequality, we see that all values of z are less than or equal to -5. This means that the solution set lies to the left of -5 on the number line. Furthermore, the inequality symbol indicates that z=-5 is a solution, which we will mark with a closed circle on the number line at -5.