If xy = 1

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by GMAT dreamer » Tue Nov 18, 2008 12:16 pm
We can make things simpler...
If xy=1; it tells that x=1 and y=1, right?

so, 2^(1+1)^2/2^(1-1)^2=
2^2^2/2^0^2=
2^4/2^0=
16/1= 16

Very simple we put numbers.

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by cramya » Tue Nov 18, 2008 3:40 pm
If xy=1; it tells that x=1 and y=1, right?
In general if xy=1 does not necessarily mean x=1 and y=1 unless there are other properties about x and y also given that confirms the fact that x=1 y=1

To quote a few:

x=-1 y=-1 xy=1

x=5 y=1/5 xy =1

x=-5 y=-1/5 xy=1

Unless it says x and y are positive integers and xy=1 we cannot assume
x=1 and y=1

Hope this helps!

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by rochy81 » Sun Aug 16, 2009 1:02 pm
Ahh, I was just stuck on this. I'm kicking myself...
Anyone happen to know what the difficulty of this question is?