
Victoria V. answered 10/09/20
20+ years teaching Algebra 2 subjects & beyond.
2|3x+2| - 12 < 0
Add 12 to both sides 2|3x+2| < 12
Divide both sides by 2 |3x+2| < 6
Now, all abs val inequalities work the same, once it is simplified to a single abs val on one side and a number on the other.
There are always 2 parts to an abs val solution. With less than, think AND - less "thand"
3x+2 < 6 AND 3x+2 > -6 NOTICE: the expression inside the vertical lines does NOT CHANGE.
What changes is the < becomes >, and the +6 becomes -6 for the second expression.
Solve each of these, keeping the AND in the solution:
Subtract 2 from both sides:
3x < 4 AND 3x > -8
Divide both sides by 3
x < 4/3 AND x > -8/3
or can write it as
-8/3 < x < 4/3

Victoria V.
I forgot the interval notation: (-8/3, 4/3)10/09/20