SOLUTION: Solve the following exponential equation: {{{2^(2x) + 2^(x+2) - 12 = 0}}}

Algebra ->  Exponential-and-logarithmic-functions -> SOLUTION: Solve the following exponential equation: {{{2^(2x) + 2^(x+2) - 12 = 0}}}      Log On


   

Question 590926: Solve the following exponential equation:
2%5E%282x%29+%2B+2%5E%28x%2B2%29+-+12+=+0
Answer by lwsshak3(11628) About Me  (Show Source):
You can put this solution on YOUR website!
Solve the following exponential equation:
2^(2x) + 2^(x+2) - 12 = 0
2^(2x) + 2^x*2^2 - 12 = 0
2^(2x) + 2^x*4 - 12 = 0
2^2x + 4*2^x - 12 = 0
.
let u=2^x
u^2=2^2x
..
u^2+4u-12=0
(u+6)(u-2)=0
u=-6=2^x
no real solution, (2^x>0)
or
u=2=2^x
x=1