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Re: exponents

by Talkativetree » Sun Oct 18, 2009 3:55 pm
heshamelaziry wrote:If x^a - b = 1, what is the value of x ?

(1) a ≠ b

(2) x > 0
My instincts tell me that the answer will be either C or E, just because looking at the problem and (1) and (2), i just can't imagine a scenario where 1 or 2 would ever be sufficient.

Now looking at them together, if x is greater than 0, then we know a few things from that. It means that X^a will be positive. this means that when X^a=1+b ; b>-1

what we also know is that x = (b+1)^(1/a).

I'm not sure where to go, this one's got me a little stumped. I am not sure exactly how you'd solve for x, but it's supposedly possible. looking forward to seeing if anyone else can solve this one
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Re: exponents

by fruti_yum » Thu Oct 22, 2009 2:27 pm
heshamelaziry wrote:If x^a - b = 1, what is the value of x ?

(1) a ≠ b

(2) x > 0

OA

[spoiler]C[/spoiler[/spoiler]
I went for E... You must most likely understand that individually statements are insuff. Together we can still have any value for x. x can be 3, b can be 8 or x can be 4 and b can be 15 to satisfy the given equation. hence the answer is E.
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Re: exponents

by life is a test » Thu Oct 22, 2009 9:59 pm
heshamelaziry wrote:If x^a - b = 1, what is the value of x ?

(1) a ≠ b

(2) x > 0

OA

[spoiler]C[/spoiler[/spoiler]
not sure about the OA being C

If we take both statements, x can be a number of different values:
e.g. a=1, b=0 so x = 1 and a=2, b=3 so x = 2
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Re: exponents

by xcusemeplz2009 » Thu Oct 22, 2009 11:26 pm
heshamelaziry wrote:If x^a - b = 1, what is the value of x ?

(1) a ≠ b

(2) x > 0

OA

[spoiler]C[/spoiler[/spoiler]

kindly check it may be x^(a-b)=1; then OA c is correct
It does not matter how many times you get knocked down , but how many times you get up
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