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Simplifying Expression using Logarithms

  • Thread starter jahaddow
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  • #1
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Simplify the attached expression using any relevant logarithmic rules

I havent really done much with logarithms, so i didnt know where to start?
 

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  • #2
rl.bhat
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Simplify the attached expression using any relevant logarithmic rules

I havent really done much with logarithms, so i didnt know where to start?
Given problem can be written as

log(2)4 + log(16)1/4 + log(1/4)2 - log(7/4)

Now use laws of logarithm to simplify.
 
  • #3
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the problem is I dont know how to do that?
 
  • #4
rl.bhat
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the problem is I dont know how to do that?
log(a) + log(b) = log(ab)

log(a) - log(b) = log(a/b)
 
  • #5
HallsofIvy
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Simplify the attached expression using any relevant logarithmic rules

I havent really done much with logarithms, so i didnt know where to start?
the problem is I dont know how to do that?
Then you should start by learning the "relevant logarithmic rules"!

[itex]log(ab)= log(a)+ log(b)[/itex]

[itex]log(a/b)= log(a)- lob(b)[/itex]

[itex]log(a^b)= b log(a)[/itex]
 
  • #6
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Can somebody please demonstrate the question?
 
  • #7
737
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No, you need to solve it yourself; you received sufficient help in the previous posts. Follow that advice.
 
  • #8
47
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That advice dosent get me anywhere!
 
  • #9
737
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Post what you have tried so far pertaining to the advice, or post and ask a question regarding the advice. If I asked you to simplify log(a) + log(b), how would you do it?
 
  • #10
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well that would be log(ab)
 
  • #11
737
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Yes, so look at the 3 logarithm rules provided by HallsofIvy and apply them to your problem.
 
  • #12
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ok so I'm up to log(2^2) + log(16^1/4) + log(1/4^2) - log(7/4)
 
  • #13
737
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Instead of log(22) it should be something else. Now, continue until you get an expression with only one log.
 
  • #14
47
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yes ok it would be log(2^4), but then I realy am stuck on what to do next!
 
  • #15
737
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well that would be log(ab)
Follow your own advice. :wink:
 
  • #16
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I dont know how to!!!!!!
 
  • #17
rl.bhat
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I dont know how to!!!!!!
OK.

What is 24, 161/4 and 42?

Substitute these values in my post #2 and simplify by using the relevant equation given by us.
 
  • #18
47
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Would the answer be log(2/1.75)
 
  • #19
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Ok, now I have one which is attached.
I have managed to get to this
logx4/logx1/3
What do I do from here?
 

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  • #20
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Or would it be 12logx? I dont know.
 
  • #21
rl.bhat
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Or would it be 12logx? I dont know.
Your answer for the first problem is correct. But write it as a single number, not in the form of a fraction.

In the second problem from where did you get log(x) along with 12?
 
  • #22
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The second problem, I worked out to be just 12 now. But the first problem, 2/1.75 equals a long decimal, so wouldnt I just leave it as a fraction?
 
  • #23
rl.bhat
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The second problem, I worked out to be just 12 now. But the first problem, 2/1.75 equals a long decimal, so wouldnt I just leave it as a fraction?
In that case you can write it as 8/7
 
  • #24
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Thankyou Very Much! :D
 
  • #25
47
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just one more question, how do I simplify this and express with positive indices.
(18x^3 X 2x^-4)/(4x^-5 X 6x)
 

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