SOLUTION: Please help with the following question, I'm about ready to yank my hair out... Let {{{ log (b, 2) }}} equal A and {{{ log (b, 3) }}} equal C. Write the expression below in term

Algebra ->  Logarithm Solvers, Trainers and Word Problems -> SOLUTION: Please help with the following question, I'm about ready to yank my hair out... Let {{{ log (b, 2) }}} equal A and {{{ log (b, 3) }}} equal C. Write the expression below in term      Log On


   



Question 683635: Please help with the following question, I'm about ready to yank my hair out...
Let +log+%28b%2C+2%29+ equal A and +log+%28b%2C+3%29+ equal C. Write the expression below in terms of A and C.
+log+%28+b%2C+sqrt+%2832%2F27%29+%29+
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I've tried +sqrt+%285A-3C%29+ But that doesn't seem to be correct

Found 2 solutions by Edwin McCravy, Alan3354:
Answer by Edwin McCravy(20060) About Me  (Show Source):
You can put this solution on YOUR website!
I think you just didn't remember that the square root is the same
as the 1%2F2 power.

+log+%28+b%2C+sqrt+%2832%2F27%29+%29+ 

We observe that 32 = 2*16 = 2*2*8 = 2*2*2*4 = 2*2*2*2*2 = 25
We observe that 27 = 3*9 = 3*3*3 = 33

+log+%28+b%2C+sqrt+%282%5E5%2F3%5E3%29+%29+

We observe that the square root is the 1%2F2 power:



Now we use a rule of logarithms that allows us to move the 1%2F2
exponent in front as a coefficient of the log:

expr%281%2F2%29log+%28+b%2C+%282%5E5%2F3%5E3%29+%29+

Now we can write the log of a quotient as the difference of the logs,
being careful to place the difference of logs in parentheses so that
the 1%2F2 is multiplied by both terms:

expr%281%2F2%29%28log+%28+b%2C+2%5E5+%29-log%28b%2C3%5E3%29+%29

Now on each of those terms inside the parentheses, we again use the
rule of logarithms that allows us to move the 5 and 2 exponents in 
front as a coefficient of the logs:

expr%281%2F2%29%285%2Alog+%28+b%2C+2+%29-3%2Alog%28b%2C3%29+%29

Finally we substuitute A for log%28b%2C2%29 and C for log%28b%2C3%29

expr%281%2F2%29%285A-3C+%29

Yoou can leave it like that or write it over 2 like this:

%285A-3C+%29%2F2

or as

5A%2F2-3C%2F2

or as

expr%285%2F2%29A-expr%283%2F2%29C%29

Edwin


Answer by Alan3354(69443) About Me  (Show Source):
You can put this solution on YOUR website!
Let +log+%28b%2C+2%29+ equal A and +log+%28b%2C+3%29+ equal C. Write the expression below in terms of A and C.
+log+%28+b%2C+sqrt+%2832%2F27%29+%29+
---------------

= %281%2F2%29log%28b%2C2%5E5%29+-+%281%2F2%29log%28b%2C3%5E3%29%29
= %285%2F2%29log%28b%2C2%29+-+%283%2F2%29log%28b%2C3%29%29
= 5A/2 - 3C/2
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or (5A - 3C)/2