SOLUTION: log(x)=log(3)+log(x-6) log(X)+log(x-5)=log(6) I really need help with this 2 problems!!! i know the answers but i need to know how to do them answer for both of them is 9

Algebra ->  Logarithm Solvers, Trainers and Word Problems -> SOLUTION: log(x)=log(3)+log(x-6) log(X)+log(x-5)=log(6) I really need help with this 2 problems!!! i know the answers but i need to know how to do them answer for both of them is 9      Log On


   



Question 311366: log(x)=log(3)+log(x-6)
log(X)+log(x-5)=log(6)
I really need help with this 2 problems!!! i know the answers but i need to know how to do them answer for both of them is 9

Answer by stanbon(75887) About Me  (Show Source):
You can put this solution on YOUR website!
log(x)=log(3)+log(x-6)
log(x) = log[3(x-6)]
x = 3(x-6)
x = 3x - 18
2x = 18
x = 9
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log(X)+log(x-5)=log(6)
log(x(x-5)) = log6
x(x-6) = 6
x^2-6x-6 = 0
x = [6+- sqrt(36 -4*-6)]/2
---
x = [6 +- sqrt(60)]/2
x = [6 +- 2sqrt(15)]/2
x = [3 +- sqrt(15)]
Positive solution:
x = 3 + sqrt(15)
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Cheers,
Stan H.
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