How was this log solved?

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Homework Statement



solve the log x²-4x-5 on the base x-2.[/B]

Homework Equations



I read a comment from someone that also saw the question that says:
making the equation equal to zero, the x values became approximately: 5.1623 and -1.1623

The Attempt at a Solution



If it was x²-4x+4, that would be igual (x-2)² and the answer would be 2, but I have no idea the guy got these broken numbers. Making what equal to zero?
the x²-4x-5? Doesn't make sense.
 

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  • #2
SammyS
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Homework Statement

[/B].

solve the log x²-4x-5 on the base x-2.

Homework Equations



I read a comment from someone that also saw the question that says:
making the equation equal to zero, the x values became approximately: 5.1623 and -1.1623

The Attempt at a Solution



If it was x²-4x+4, that would be igual (x-2)² and the answer would be 2, but I have no idea the guy got these broken numbers. Making what equal to zero?
the x²-4x-5? Doesn't make sense.
First of all: There is no equation to be solved in your thread.

Second: x2 − 4x − 5 can be factored quite nicely.

Third: What do you mean by " base x-2 " ?

Added in Edit:

Fourth: x = 5.1623 , −1.1623 are approximate solutions to x2 − 4x − 6 = 0 .
 
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  • #3
haruspex
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Where does the question come from?
 
  • #4
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First of all: There is no equation to be solved in your thread.
Third: What do you mean by " base x-2 " ?

It's the base of the log, [itex](x-2) ^ {y} = x² -4x -5[/itex]. The statement is to solve it.

Where does the question come from?

From a video where the presenter receives random questions about several subjects. Someone asked it, a comment about it mentioned the roots and I got curious about whether this has a solution or not.
 
  • #5
haruspex
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It's the base of the log, [itex](x-2) ^ {y} = x² -4x -5[/itex]. The statement is to solve it.



From a video where the presenter receives random questions about several subjects. Someone asked it, a comment about it mentioned the roots and I got curious about whether this has a solution or not.
Ok, so we should not be too surprised that the question makes no sense.
 

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