SOLUTION: How can I solve this log equation? 2log<base3>(x+4)-log<base3>9=2 So far I have this: logbase3(x+4)^2 minus logbase3 9=2 logbase3=(x+4)^2 divided by 9 =2 3^2(x+4)^2 divided by

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Question 531039: How can I solve this log equation? 2log(x+4)-log9=2
So far I have this:
logbase3(x+4)^2 minus logbase3 9=2
logbase3=(x+4)^2 divided by 9 =2
3^2(x+4)^2 divided by 9
9(x+4)^2 divided by 9
divide by 9 on both sides
81=(x+4)^2 = (x+2)(x+2)
I'm not sure where I am not doing it right.
Thanks for you're help
Answer by lwsshak3(11628) (Show Source):
You can put this solution on YOUR website!
How can I solve this log equation? 2log(x+4)-log9=2
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2log(x+4)-log9=2
note: when the base not indicated, it is assumed to be base 10.
place under single log
log[(x+4)^2/9]=2
convert to exponential form: Base(10) raised to log of number(2)=number[(x+4)^2/9]
10^2=[(x+4)^2/9]=100
(x+4)^2=900
x^2+8x+16=900
x^2+8x-884=0
(x+34)(x-26)=0
x=-34 (reject, (x+4)>0)
or
x=26

use following quadratic equation if factoring difficult.
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