Lesson 3-7
Part 2
Absolute Value Inequalities
Sept. 2, 2014
Daily Learning Target
•I will solve inequalities
involving absolute
value.
Key Concept
• Remember: You need to think about
inequalities two possible ways: “and” “or”
• If the original inequality is a < then we will
work the inequality as an “and” inequality.
• If the original inequality is a > then we will
work the inequality as an “or” inequality.
Key Concept cont.
• To solve an inequality in the form 𝐴 < b,
where A is a variable expression and b > 0,
solve the compound inequality –b < A < b.
• To solve an inequality in the form 𝐴 > b,
where A is a variable expression and b > 0,
solve the compound inequality A < -b or A > b.
• Same rules apply for 𝐴 ≤ b or 𝐴 ≥ b.
Example 1
8𝑛 ≥ 24
Answer: n ≤ -3 or n ≥ 3
Example 2
𝑥+3 <5
Answer: -8 < x < 2
Example 3
A company makes boxes of crackers that should
weigh 213 g. A quality-control inspector
randomly selects boxes to weigh. Any box that
varies from the weight by more than 5 grams is
sent back. What is the range of allowable
weights for a box of crackers.
Answer: 208 ≤ w ≤ 218
Classwork
• Lets take a look at some problems to practice
before homework is assigned.
• This will be counted as a completion grade (10
points) that will need to be turned in before
leaving class.
Homework
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Page 103
Problems: 18, 20, 21, 22, 30
Page 105
Problems: 1-6 ALL