Question 951174: find x
show working please
log (x+5)=log 4 - log (x+2)
Answer by stanbon(75887)   (Show Source):
You can put this solution on YOUR website! log (x+5)=log 4 - log (x+2)
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log(x+5) + log(x+2) = log(4)
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log[(x+5)(x+2)] = log(4)
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x^2 + 7x + 10 = 4
x^2 + 7x + 6 = 0
Factor:
(x+6)(x+1) = 0
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Acceptable solution::
x = -1
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Note:: The other solution--- x = -6 ------ makes (x+2) and (x+5) negative.
You cannot take the log of a negative.
Cheers,
stan H.
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