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If x^2 − kx + 24 = 0, is x = −6? [#permalink]
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05 Nov 2014, 08:20
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If x^2 − kx + 24 = 0, is x = −6? (1) (x+6) is a factor of x^2k·x+24=0, where k is a constant, and x is a variable. (2) (x+4) is a factor of x^2k·x+24=0, where k is a constant, and x is a variable.
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Re: If x^2 − kx + 24 = 0, is x = −6? [#permalink]
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05 Nov 2014, 08:24
x^2−k·x+24=0 Solving the equation we get x = 6 or 4 Statement 1) (1) (x+6) is a factor of x^2k·x+24=0, where k is a constant, and x is a variable. We already know that (x+6) is a factor of equation. No new information to determine if x = 6 2) (x+4) is a factor of x^2k·x+24=0, where k is a constant, and x is a variable. We already know that (x+4) is a factor of equation. No new information to determine if x = 6 Combining. (x+6) and (x+4) are factors > No new information to determine if x = 6 hence E)
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Re: If x^2 − kx + 24 = 0, is x = −6? [#permalink]
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05 Nov 2014, 08:36



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Re: If x^2 − kx + 24 = 0, is x = −6? [#permalink]
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05 Nov 2014, 11:00
Hi kinjiGC , How did u derive the values x = 6 or x = 4 from the question stem itself ? Can u please elaborate ?



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Re: If x^2 − kx + 24 = 0, is x = −6? [#permalink]
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23 Nov 2014, 09:01
I think it is not possible to get the solution of the equation from stem as specified by kinji:
from statement 1: x+6 is a factor of x^2kx+24 = 0, substitute x = 6 and we get the value of k as 10 , from this the roots of the equation x^210x+24 = 0 are 4 and 6, so NSF from statement 2: we have the same result NSF combined x = 4 or 6 so, NSF
E



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Re: If x^2 − kx + 24 = 0, is x = −6? [#permalink]
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08 Oct 2017, 02:14
For x2−k·x+24=0, pairs of roots can be (6,4),(6,4),(12,2) and (8,3) etc. 1) We have been told that (x+6) is a root so our pair is (6,4). Here two values of x can be possible. Not Sufficient. 2) Same as statement 1.
1& 2 together not sufficient.




Re: If x^2 − kx + 24 = 0, is x = −6?
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08 Oct 2017, 02:14






