ABSOLUTE VALUE INEQUALITIES
Jan 17, 2016
ABSOLUTE VALUE INEQUALITIES
ABSOLUTE VALUE INEQUALITIES
Just like absolute value equations,
inequalities will have two solutions: |3x -
2| ≤ 7 3x – 2 ≤ 7 +2 +2 3x ≤ 9 x ≤ 3
-5/3 ≤ x ≤ 3[ -5/3, 3 ]
-7 ≤ 3x – 2+2 +2 -5 ≤ 3x -5/3 ≤ x
-7≤ 3x – 2 ≤ 7
ABSOLUTE VALUE INEQUALITIES
Try again:
|2x + 1| < 11
-11 < 2x +1
AND
-12 < 2x
-6 < x
2x +1 < 11
2x < 10
x < 5
-6 < x < 5 ( -6, 5 )
ABSOLUTE VALUE INEQUALITIES
If the sign is less than, the answer is written as
one statement.• |2x + 1| < 11
• -6 < x < 5 (-6, 5)
If the sign is greater than, the answer must be
written as two statements.• See the next problem.
ABSOLUTE VALUE INEQUALITIES
|1 – 2x| > 5
1 – 2x > 5
-1 -1
-2x > 4
x < -2
OR 1 – 2x < -5
-1 -1
-2x < -6
x > 3
x < -2 or x > 3(-∞, -2) U ( 3, ∞)
ABSOLUTE VALUE INEQUALITIES
Practice these:
|2x - 5| < 6
|3x + 6| ≤ 3
|x - 5| > 4
|2x + 5|≥ 8