Absolute X inequalities MGMAT 700-800 problem

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Source: — Data Sufficiency |

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by tohellandback » Tue Jul 21, 2009 6:44 pm
IMO B
1) -2<x<2 not sufficient

2)when x >0
x=1
when x<0
x=1/2 which is >0(contradiction). SUFFICIENT
The powers of two are bloody impolite!!

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by fruti_yum » Fri Aug 21, 2009 12:57 pm
tohellandback wrote:IMO B
1) -2<x<2 not sufficient

2)when x >0
x=1
when x<0
x=1/2 which is >0(contradiction). SUFFICIENT
for b when you get the two values.. x = 1/2 or x = 1..

try plugging it in the orginal equation.. you'll quickly see that 1/2 does not work..so we're left with one and only 1 value for x..

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by tohellandback » Fri Aug 21, 2009 1:39 pm
fruti_yum wrote:
tohellandback wrote:IMO B
1) -2<x<2 not sufficient

2)when x >0
x=1
when x<0
x=1/2 which is >0(contradiction). SUFFICIENT
for b when you get the two values.. x = 1/2 or x = 1..

try plugging it in the orginal equation.. you'll quickly see that 1/2 does not work..so we're left with one and only 1 value for x..
well why do you have to plugin?
We were looking for x<0 and we got x>0. That's sufficient to say that x=1/2 does not satisfy
The powers of two are bloody impolite!!