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ABsolute values

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ABsolute values

by doclkk » Wed Aug 12, 2009 8:35 am
If |x - 1| - |x - 2| = 0, then x =?

A. 0
B. 2/3
C. 1
D. 1/2
E. 3/2

(E)

I don't know how to do the subtraction in this equation so I just plugged in the answer choices.

How to actually do the math?
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by sreak1089 » Wed Aug 12, 2009 8:43 am
I did it with Algebra, this way but not sure my approach is right:

|x - 1| - |x - 2| = 0
=> |x-1| = |x-2|
=> either x -1 = x -2 (wich does not make sense)
or x -1 = -(x-2) or -(x-1) = (x-2)
=>x - 1 = -x + 2 =>-x+1 = x-2
=> 2x = 3 => x = 3/2 => 3 = 2x => x = 3/2
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by tohellandback » Wed Aug 12, 2009 7:32 pm
distance from X to 1 is equal to distance from x to 2
X must be between 1 and 2
answer E
The powers of two are bloody impolite!!
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