How do I solve this exponential equation: 9^x + 3^(x + 1) - 40 = 0
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How do I solve this exponential equation: 9^x + 3^(x + 1) - 40 = 0

[From: ] [author: ] [Date: 12-09-20] [Hit: ]
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I am asked to provide exact answers only and I came up with the solution of {2}, but I'm not sure if this is correct. I change it to be in quadratic form, but I wasn't sure what to do with the 1 that is attached to the x. I really need help with this.

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9^x + 3^(x + 1) - 40 = 0

3^(2x) + 3(3^x) - 40 = 0

(3^x + 8)(3^x - 5) = 0

3^x = -8(Not possible)

3^x = 5 => x = ln(5)/ln(3)
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