Big Ideas Math Algebra 1, 2015
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Big Ideas Math Algebra 1, 2015 View details
6. Solving Absolute Value Inequalities
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Exercise 8 Page 91

Create an or compound inequality because the absolute value is greater than the given value.

Solution Set: c<-3 or c>3
Graph:

Practice makes perfect
We are asked to find and graph the solution set for all possible values of c in the given inequality. |4c+5|>7 To do this, we will create a compound inequality by removing the absolute value. In this case, and since 4c+5 can be written as 4c-(- 5), the solution set contains the numbers that make the distance between 4c and - 5 greater than 7 in the positive direction or in the negative direction. 4c+5 > 7 or 4c+5 < - 7

Let's isolate c 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.
4c+5 > 7
4c > 12
c>3
This inequality tells us that all values greater than 3 will satisfy the inequality.

Case 2

Now, let's solve the second case of the inequality.
4c+5 < - 7
4c < - 12
c<-3
This inequality tells us that all values less than - 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:& c>3 Second Solution Set:& c< -3 Combined Solution Set:& c< -3 or c>3

Graph

The graph of this inequality includes all values less than - 3 or greater than 3. We show this by using open circles on the endpoints.