GMATPrep Help

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GMATPrep Help

by mpaudena » Tue Oct 20, 2009 8:21 pm
Is Sqrt(x-3)^2 = 3 - x?

1) x does not equal 3

2) -x|x|

Please explain how to find statement 1 insufficient. Thanks in advance.

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by sanjana » Wed Oct 21, 2009 1:00 am
Is the statement 2 complete?

The question asks is
sqrt(x-3)^2 = 3-x

i.e,is |x-3|=3-x?

sqrt(x^2)=|x|

Statement 1
-----------
x not eq 3

x=2,then |x-3|=3-x
x=4,then |x-3|not equal to 3-x
Hence Insufficient.

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by mpaudena » Wed Oct 21, 2009 6:41 am
I'm sorry. Statement 2 is incomplete: -x|x| > 0.

Also, Sanjana, I don't know if you've stopped watching this topic but please take a look at this (https://www.beatthegmat.com/percent-prob ... tml#198038) as I am still having problems with it. Thanks.

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by life is a test » Fri Oct 23, 2009 12:10 am
IMO B

the question reworded (since square root of a number is always >0): |x-3| = 3 - x?
if x-3 >0; x>3
if x-3 <0; x<3

1) insuff since it doesnt tell us if x>3 or x<3

2) suff since it tells us x<0 in which case it is <3