SOLUTION: solve for x: 2^(2x) + 2^(x+2) - 12 = 0, I believe logarithms are needed.

Algebra ->  Exponential-and-logarithmic-functions -> SOLUTION: solve for x: 2^(2x) + 2^(x+2) - 12 = 0, I believe logarithms are needed.      Log On


   

Question 464911: solve for x: 2^(2x) + 2^(x+2) - 12 = 0, I believe logarithms are needed.
Answer by Alan3354(69443) About Me  (Show Source):
You can put this solution on YOUR website!
x = 1
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The hard way:
2%5E%282x%29+%2B+2%5E%28x%2B2%29+-+12+=+0
2%5Ex%2A%282%5Ex+%2B+4%29+-+12+=+0
2%5E2x+%2B+4%2A2%5Ex+-+12+=+0
Sub y for 2^2
y%5E2+%2B+4y+-+12+=+0
(y+6)*(y-2) = 0
y = 2^x = -6, 2
Ignore the -6
2^x = 2
x = 1