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sachin.w
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2 conflicting interpretations/rephasings of a Question

by sachin.w Fri Sep 21, 2012 6:38 am

Have a doubt with regards to mods..

say Question is squareroot[(x-5)^2]=5-x?

Now,
since on gmat, squareroot of negative numbers don't exist, this Question can be rephrased as
is (x-5) > 0?
or x>5?--------------1

but
since squareroot[(x-5)^2] is |(x-5)|, Question can be rephrased as
is |(x-5)|=5-x?
now since |(x-5)| cant be negative,
it can again be rephrased as
is 5-x>=0?
which is
is 5>=x?
or
is x<=5?------------2

How can there be 2 ( 1 & 2) interpretations ? I guess I am missing something here ... Please help..
tim
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Re: 2 conflicting interpretations/rephasings of a Question

by tim Wed Sep 26, 2012 11:31 am

your first rephrasing is wrong and doesn't follow at all from any mathematical conventions used on the GMAT..
Tim Sanders
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