Inactive Tutor answered 07/25/13
Definition of the absolute value:
| a | = a, if a ≥ 0
| a | = - a, if a < 0
(for example: | 5 | = 5
| -5 | = - (-5) = 5 )
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| 5 - 3x | + 3 ≥ 7
First, let's simplify an inequality
| 5 - 3x | ≥ 7 - 3
| 5 - 3x | ≥ 4
1. Let's assume that (5 - 3x) ≥ 0 , then
5 - 3x ≥ 4
- 3x ≥ 4 - 5 = -1
÷ (-3) ÷ (-3)
x ≤ 1/3 , or any number out of (- ∞, 1/3]
2. Let's assume, that (5 - 3x) is negative (< 0) , then
– (5 - 3x) ≥ 4
- 5 + 3x ≥ 4
3x ≥ 4 + 5 = 9
x ≥ 3 , or any number out of [3, ∞)
The answer is any number out of (- ∞, 1/3] U [3, ∞)