SOLUTION: We have tried and tried to find the answer, but can't seem to figure out when to use the multipicative inverse to solve it. The problem is: 2^2x = 8^(x-1) Hope you can help. Tha

Algebra ->  Exponents-negative-and-fractional -> SOLUTION: We have tried and tried to find the answer, but can't seem to figure out when to use the multipicative inverse to solve it. The problem is: 2^2x = 8^(x-1) Hope you can help. Tha      Log On


   



Question 101910: We have tried and tried to find the answer, but can't seem to figure out when to use the multipicative inverse to solve it. The problem is:
2^2x = 8^(x-1) Hope you can help. Thanks!

Answer by stanbon(75887) About Me  (Show Source):
You can put this solution on YOUR website!
The problem is:
2^2x = 8^(x-1)
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Write both sides to the base 2 as follows:
2^(2x) = (2^3)^(x-1)
2^2x = 2^[3x-3]
Since the bases are the same the exponents are equal.
2x = 3x-3
-x = -3
x = 3
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Cheers,
Stan H.