SOLUTION: Please help me solve this equation: 2log7(x-1)=4log7(2)

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Question 319944: Please help me solve this equation: 2log7(x-1)=4log7(2)
Answer by ankor@dixie-net.com(22740) About Me  (Show Source):
You can put this solution on YOUR website!
2log7(x-1)=4log7(2)
Use the exponent form
log7((x-1)^2) = log7(2^4)
FOIL
log7(x^2-2x+1) = log7(16)
Therefore:
x^2 - 2x + 1 = 16
:
x^2 - 2x + 1 - 16 = 0
:
x^2 - 2x - 15 = 0
Factor
(x-5)(x+3) = 0
Two solutions, but only the positive solution will work here
x = 5
:
:
You can confirm this:
log7((5-1)^2) = log7(2^4)
log7(4^2) = log7(16)