Question 598413: solve for x:
(e^2x)-36=16e^x
Answer by stanbon(75887)   (Show Source):
You can put this solution on YOUR website! solve for x:
(e^2x)-36=16e^x
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That is a quadratic in e^x:
(e^x)^2 - 16e^x - 36 = 0
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Let e^x = w
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w^2 - 16w - 36 = 0
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w^2-18w+2w-36 = 0
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w(w-18) + 2(w-18) = 0
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(w-18)(w+2) = 0
w = 18 or w = -2
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e^x = 18 or e^x = -2
Note: e^x cannot be negative.
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Solve e^x = 18
x = ln(18)
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Cheers,
Stan H.
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