Suppose x is an integer such that (x ^ 2 −x−1)^ (x+2) =1 . How many possible values of x exist?
1
2
3
4
5
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Number properties
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GMATinsight
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(x ^ 2 −x−1)^ (x+2) =1 is possible only whensud21 wrote:Suppose x is an integer such that (x ^ 2 −x−1)^ (x+2) =1 . How many possible values of x exist?
1
2
3
4
5
Either (x ^ 2 −x−1)=1 i.e. x = 2 or -1
OR (x+2) =0 i.e. x = -2
Or x=0
i.e. Possible values of x = 0, 2, -1 and -2
Answer: option D
Last edited by GMATinsight on Fri Oct 09, 2015 10:31 pm, edited 1 time in total.
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Hi sud21,
As complex as this question looks, it's really just about some fundamental Exponent rules.
Before working through the Algebra, it's important to define HOW the given Exponent-equation can equal 1:
1) (1)^(any) = 1
2) (any)^(0) = 1
3) (-1)^(even) = 1
Knowing these rules, how many distinct values of X fit the given equation? Remember to be thorough with your Algebra....
Final Answer: D
GMAT assassins aren't born, they're made,
Rich
As complex as this question looks, it's really just about some fundamental Exponent rules.
Before working through the Algebra, it's important to define HOW the given Exponent-equation can equal 1:
1) (1)^(any) = 1
2) (any)^(0) = 1
3) (-1)^(even) = 1
Knowing these rules, how many distinct values of X fit the given equation? Remember to be thorough with your Algebra....
Final Answer: D
GMAT assassins aren't born, they're made,
Rich
