GMAT Prep algebra
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- lunarpower
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wait what?
something is seriously wrong here, as elementary number picking is quick to show.
first off, the 2's clearly cancel, so get rid of them.
if we let x = 2 and y = 1/2, then the expression is (5/2)^2 / (3/2)^2, which is 25/9 = 2.77777..., an answer that is clearly not listed. worse yet, plugging in other numbers leads to other answer choices.
incidentally, the only numbers that satisfy the initial constraint (xy = 1) and actually give the answer 16 are plus or minus (√15)/5 and (√15)/3 - two numbers that, i can confidently say, no one is going to pick anytime soon.
something is seriously wrong here, as elementary number picking is quick to show.
first off, the 2's clearly cancel, so get rid of them.
if we let x = 2 and y = 1/2, then the expression is (5/2)^2 / (3/2)^2, which is 25/9 = 2.77777..., an answer that is clearly not listed. worse yet, plugging in other numbers leads to other answer choices.
incidentally, the only numbers that satisfy the initial constraint (xy = 1) and actually give the answer 16 are plus or minus (√15)/5 and (√15)/3 - two numbers that, i can confidently say, no one is going to pick anytime soon.
Ron has been teaching various standardized tests for 20 years.
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Quand on se sent bien dans un vêtement, tout peut arriver. Un bon vêtement, c'est un passeport pour le bonheur.
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- lunarpower
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wait, uh, well, i made up a problem that looks at least somewhat like this one, with the desired solution.
here you go:
![Image](https://img2.freeimagehosting.net/uploads/th.304727c54d.jpg)
here you go:
![Image](https://img2.freeimagehosting.net/uploads/th.304727c54d.jpg)
Ron has been teaching various standardized tests for 20 years.
--
Pueden hacerle preguntas a Ron en castellano
Potete chiedere domande a Ron in italiano
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Voit esittää kysymyksiä Ron:lle myös suomeksi
--
Quand on se sent bien dans un vêtement, tout peut arriver. Un bon vêtement, c'est un passeport pour le bonheur.
Yves Saint-Laurent
--
Learn more about ron
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Pueden hacerle preguntas a Ron en castellano
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Voit esittää kysymyksiä Ron:lle myös suomeksi
--
Quand on se sent bien dans un vêtement, tout peut arriver. Un bon vêtement, c'est un passeport pour le bonheur.
Yves Saint-Laurent
--
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- simplyjat
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This question is a mistake in GMATPrep, The original intent of the question is to ask
If XY = 1
Than what is the value of (2^[(x+y)^2])/(2^[(x-y)^2]) ?
Which simplifies to
(2^(x^2))*(2^(y^2))*(2^(2xy)) / (2^(x^2))*(2^(y^2))*(2^(-2xy))
=> (2^(2xy)) / (2^(-2xy))
=> (2^(4xy))
=> (2^(4*1))
=> 2^4
=> 16
If XY = 1
Than what is the value of (2^[(x+y)^2])/(2^[(x-y)^2]) ?
Which simplifies to
(2^(x^2))*(2^(y^2))*(2^(2xy)) / (2^(x^2))*(2^(y^2))*(2^(-2xy))
=> (2^(2xy)) / (2^(-2xy))
=> (2^(4xy))
=> (2^(4*1))
=> 2^4
=> 16
simplyjat
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- lunarpower
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that's awesomesimplyjat wrote:This question is a mistake in GMATPrep, The original intent of the question is to ask
If XY = 1
Than what is the value of (2^[(x+y)^2])/(2^[(x-y)^2]) ?
Which simplifies to
(2^(x^2))*(2^(y^2))*(2^(2xy)) / (2^(x^2))*(2^(y^2))*(2^(-2xy))
=> (2^(2xy)) / (2^(-2xy))
=> (2^(4xy))
=> (2^(4*1))
=> 2^4
=> 16
where'd you get the fix? did you figure it out yourself?
Ron has been teaching various standardized tests for 20 years.
--
Pueden hacerle preguntas a Ron en castellano
Potete chiedere domande a Ron in italiano
On peut poser des questions à Ron en français
Voit esittää kysymyksiä Ron:lle myös suomeksi
--
Quand on se sent bien dans un vêtement, tout peut arriver. Un bon vêtement, c'est un passeport pour le bonheur.
Yves Saint-Laurent
--
Learn more about ron
--
Pueden hacerle preguntas a Ron en castellano
Potete chiedere domande a Ron in italiano
On peut poser des questions à Ron en français
Voit esittää kysymyksiä Ron:lle myös suomeksi
--
Quand on se sent bien dans un vêtement, tout peut arriver. Un bon vêtement, c'est un passeport pour le bonheur.
Yves Saint-Laurent
--
Learn more about ron
- simplyjat
- Master | Next Rank: 500 Posts
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Actually the correct question is stated in OG. I can't remember the exact question number, but I remember solving the question from one of the books...
simplyjat
- simplyjat
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Yesterday, I was giving the GMAT prep and the same question popped up for me. But amazingly the formatting was correct! It seems that there can be a problem with your GMATPrep setup.
vinviper1 can you let us know the setup: Operating System and Java Run-time version. To see the version of windows right-click "My computer" and select "Properties". To see the version of Java run time environment, on command prompt type "java -version".
It would be really helpful for other people...
vinviper1 can you let us know the setup: Operating System and Java Run-time version. To see the version of windows right-click "My computer" and select "Properties". To see the version of Java run time environment, on command prompt type "java -version".
It would be really helpful for other people...
simplyjat