SOLUTION: 16^x+4^(x+1)-3=0 need help solving and getting the answer.

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Question 888937: 16^x+4^(x+1)-3=0
need help solving and getting the answer.
Answer by Fombitz(32388) About Me  (Show Source):
You can put this solution on YOUR website!
16%5Ex%2B4%5E%28x%2B1%29-3=0
%284%5E2%29%5Ex%2B4%5E%28x%2B1%29-3=0
4%5E%282x%29%2B4%2A4%5E%28x%29-3=0
Substitute, let u=4%5Ex
u%5E2%2B4u-3=0
%28u%5E2%2B4u%2B4%29-3-4=0
%28u%2B2%29%5E2=7
u%2B2=0+%2B-+sqrt%287%29
u=-2+%2B-+sqrt%287%29
4%5Ex=-2+%2B-+sqrt%287%29
Only the positive solution makes sense for this problem.
4%5Ex=sqrt%287%29-2
highlight%28x=log%28%28sqrt%287%29-2%29%29%2Flog%28%284%29%29%29