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Mathematics 7 Online
OpenStudy (jojokiw3):

How do I do this logarithmic equation?

OpenStudy (jojokiw3):

\[\log_{6} (x-1) + \log_{6} (x-2) = 2 \log_{6} \sqrt6 \]

zepdrix (zepdrix):

log ruuuules :) yaaaaa

zepdrix (zepdrix):

\[\Large\rm \log(a)+\log(b)=\log(ab)\]\[\Large\rm b \log(a)=\log(a^b)\]Looks like we'll need to use these two rules

OpenStudy (jojokiw3):

\[x^2 - 3x + 2 = 1\]

OpenStudy (jojokiw3):

?

zepdrix (zepdrix):

=6 I think. Hmm thinking about the step you got stuck on..

zepdrix (zepdrix):

\[\Large\rm \log_6(stuff)=1\]Therefore,\[\Large\rm 6^1=stuff\]Yah?

OpenStudy (jojokiw3):

\[2 \log_6 \sqrt 6 = \log_6 6 = 6^1 = 6?\]

zepdrix (zepdrix):

No.\[2 \log_6 \sqrt 6 = \log_6 6 = 1\]

OpenStudy (jojokiw3):

o.o where do I get the six from then?

zepdrix (zepdrix):

But the other side of your equation is:\[\Large\rm \log_6(x^2-3x+2)\]That whole thing equals 1.\[\Large\rm \log_6(x^2-3x+2)=1\]You don't have x^2-3x+2=1 at this point. You still have your log

zepdrix (zepdrix):

You have to convert to exponential form to get rid of the log.

OpenStudy (jojokiw3):

ahhh. I see what I missed. \[6^1 = x^2 - 3x +2\]

zepdrix (zepdrix):

Yeaaa boyyyy, there we go!

OpenStudy (jojokiw3):

Wheewww. I really need to get all these rules memorized completely. Thanks!

OpenStudy (jojokiw3):

x = 4.

zepdrix (zepdrix):

Because the x=-1 is extraneous? Ok looks good! :)

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