SOLUTION: Can you explain how to solve logarithmic expressions so that they are single logarithms? Example: How would you solve: log 15+ log 8 as a single expression.

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Question 757382: Can you explain how to solve logarithmic expressions so that they are single logarithms?
Example:
How would you solve:
log 15+ log 8 as a single expression.
Found 3 solutions by MathLover1, stanbon, josmiceli:
Answer by MathLover1(20850)   (Show Source):
You can put this solution on YOUR website!

Answer by stanbon(75887)   (Show Source):
You can put this solution on YOUR website!
log 15+ log 8 as a single expression.
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Log Laws:
log(A) + log(B) = log[A*B]
log(A) - log(B) = log[A/B]
log[A^n] = n*log[A]
logA{B] = log(B)/log(A)
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These are the laws you must learn.
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Your problem:
log(15) + log(8) = log(15*8) = log(120)
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Cheers,
Stan H.
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Answer by josmiceli(19441)   (Show Source):
You can put this solution on YOUR website!
The rule is:

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You can see this very well if you use
logs to the base
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Suppose the equation is:

which is

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Applying the rule:

and

so, the rule works.
In words, the rule says, " Add the logs of 2 numbers
and you will get the
same result if you multiply the 2 numbers
themselves and then take the log of that product.
Hope this helps