pre calculus

solve the equation. give an exact solution, and also an approximate solution to four decimal places.

2^(9x-7)=7

My first step was to change it to
log(base 2) 7 = 9x-7
i got 1.0897
Did i do something wrong or did i miss one question?

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1. just take log of both sides

log (2^(9x-7)) = log 7
(9x-7) log2 = log7
9x - 7 = log7/log2
etc.

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posted by Reiny
2. [9x -7] log 2 = log 7
Any log base can be used, as long as it is the same for both sides.
9x - 7 = 2.807
9x = 9.807
x = 1.0897

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posted by drwls

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