Is |x| < 1 ?
(1) |x + 1| = 2|x - 1|
(2) |x - 3| ≠0
Statement 1: |x + 1| = 2|x - 1|
Case 1: No signs changed
x+1 = 2(x-1)
x+1 = 2x - 2
3 = x.
Case 2: Signs changed in ONE of the absolute values
-(x+1) = 2(x-1)
-x-1 = 2x - 2
-3x = -1
x = 1/3.
Since |x|>1 in Case 1 but |x|<1 in Case 2, INSUFFICIENT.
Statement 2: |x - 3| ≠0
In other words, x≠3.
If x=0, then |x|<1.
If x=10, then |x|>1.
INSUFFICIENT.
Statements combined:
Statement 1 requires that x=3 or x=1/3.
Statement 2 requires that x≠3.
Thus, x=1/3, with the result that |x| < 1.
SUFFICIENT.
The correct answer is
C.
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