SOLUTION: In the equation logx 4 + logx 9 = 2, what is x equal to?

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Question 112835: In the equation logx 4 + logx 9 = 2, what is x equal to?
Found 2 solutions by jim_thompson5910, solver91311:
Answer by jim_thompson5910(35256)   (Show Source): You can put this solution on YOUR website!
Start with the given equation


Combine the logarithms using the identity


Multiply


Rewrite the logarithm in exponent form. In other words, use: ===>



Now take the square root of both sides


So our answer is


Answer by solver91311(24713)   (Show Source): You can put this solution on YOUR website!
First let's start with the basic logarithmic identity:



Using that, we can say:



But we also know that is equivalent to saying:



So, taking the square root of both sides, .

Note that -6 which satisfies our equation , cannot be a solution because the definition of the logarithm function says that the base must be greater than zero.

Hope this helps.
John

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