Big Ideas Math Integrated I, 2016
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Big Ideas Math Integrated I, 2016 View details
6. Solving Absolute Value Inequalities
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Exercise 6 Page 89

Create an or compound inequality because the absolute value needs to be greater than the given value.

Solution Set: d≤-3 or d≥1
Graph:

Practice makes perfect
We are asked to find and graph the solution set for all possible values of d in the given inequality. 3|d+1|-7≥ -1 To do this, let's isolate the absolute value expression first.
3|d+1|-7≥ -1
3|d+1|≥ 6
|d+1|≥ 2

Now, we will create a compound inequality by removing the absolute value. In this case, and since d+1 can be written as d-(- 1), the solution set contains the numbers that make the distance between d and - 1 greater than or equal to 2 in the positive direction or in the negative direction. d+1 ≥ 2 or d+1≤ - 2 Let's isolate d in both of these cases before graphing the solution set.

Case 1

We can solve the inequality by performing inverse operations on both sides of the inequality. Let's solve the first case.
d+1 ≥ 2
d≥ 1
This inequality tells us that all values greater than or equal to 1 will satisfy the inequality.

Case 2

Now, let's solve the second case of the inequality.
d+1≤ - 2
d≤ - 3
This inequality tells us that all values less than or equal to - 3 will satisfy the inequality.

Solution Set

The solution to this type of compound inequality is the combination of the solution sets. First Solution Set:& d≥ 1 Second Solution Set:& d≤ - 3 Combined Solution Set:& d≤ - 3 or d≥ 1

Graph

The graph of this inequality includes all values less than or equal to - 3 or greater than or equal to 1. We show this by keeping the endpoints closed.