SOLUTION: Find all real solutions: 4^x-5(2^x)-24=0

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Question 1086562: Find all real solutions:
4^x-5(2^x)-24=0
Answer by Alan3354(69443) About Me  (Show Source):
You can put this solution on YOUR website!
4^x-5(2^x)-24=0
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2^(2x) - 5*2^x - 24 = 0
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Sub u for 2^x
u^2 - 5u - 24 = 0
(u-8)*(u+3) = 0
u = -3
2^x = -3 Not allowed
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u = 8
2^x = 8
x = 3