SOLUTION: 8^(x+5)=4^(x) solve to find x

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Question 420792: 8^(x+5)=4^(x)
solve to find x
Answer by richard1234(7193) About Me  (Show Source):
You can put this solution on YOUR website!
We can write 8%5E%28x%2B5%29 as %282%5E3%29%5E%28x%2B5%29 --> 2%5E%283x%2B15%29. Also, 4%5Ex+=+%282%5E2%29%5Ex+=+2%5E%282x%29. Hence,

2%5E%283x%2B15%29+=+2%5E%282x%29 The exponents must be equal (we can take the logarithm of both sides)

3x%2B15+=+2x --> x+=+-15.