Question 1061106: How do you solve this?
2log3 X-log3(X+4) = 2
Answer by rothauserc(4718)   (Show Source):
You can put this solution on YOUR website! 2log3 X-log3(X+4) = 2
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log(3) (x^2 / (x+4)) = 2
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Note that 2log(3) x = log(3) x^2, also used log definition of division
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x^2 / (x+4) = 3^2 = 9
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Note used definition of logarithm
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x^2 = 9(x+4)
:
x^2 -9x -36 = 0
:
(x+3) * (x-12) = 0
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x = 12
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Note the logarithm of a negative number is not defined
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