SOLUTION: solve for x e^2x - 2e^x - 8 = 0

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Question 758391: solve for x
e^2x - 2e^x - 8 = 0
Answer by lwsshak3(11628) About Me  (Show Source):
You can put this solution on YOUR website!
solve for x
e^2x - 2e^x - 8 = 0
let u=e^x
u^2=e^2x
u^2-2u-8=0
(u-4)(u+2)=0
u=-2=e^x
e^x=-2 (reject, e^x>0)
or
u=4=e^x
e^x=4
xlne=ln4
x=ln4≈1.3863..