SOLUTION: Solve the logarithm equation. Type exact answer. 2logx-log(4x-40)-1=0

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Question 1113030: Solve the logarithm equation. Type exact answer. 2logx-log(4x-40)-1=0
Answer by Alan3354(69443) About Me  (Show Source):
You can put this solution on YOUR website!
2logx-log(4x-40)-1=0
If it's base 10:
log(x^2)-log(4x-40) = 1 = log(10)
log(x^2)-log(4x-40) = 1 = log(10)
log(x^2) = log(4x-40) + log(10)
log(x^2) = log(10*(4x-40)) = log(40x - 400)
x^2 = 40x - 400
x^2 - 40x + 400 = 0
(x-20)^2 = 0
x = 20