SOLUTION: Hey - I can normally solve this type of problem but this one has me stuck: 2e^2x+5e^x-12=0 Apparently the answer is (ln3)/2. I'm not sure why it's not ln(3/2) or even ln3-ln2

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Question 468400: Hey - I can normally solve this type of problem but this one has me stuck:
2e^2x+5e^x-12=0
Apparently the answer is (ln3)/2. I'm not sure why it's not ln(3/2) or even ln3-ln2=ln1=0. An explanation would be so very much appreciated!
Thanks,
Jess

Answer by lwsshak3(11628)   (Show Source): You can put this solution on YOUR website!
2e^2x+5e^x-12=0
Apparently the answer is (ln3)/2. I'm not sure why it's not ln(3/2) or even ln3-ln2=ln1=0. An explanation would be so very much appreciated!
...
2e^2x+5e^x-12=0
let x=e^x
x^2=e^2x
..
2x^2+5x-12=0
(2x-3)(x+4)=0
x=3/2
or
x=-4
..
e^x=-4 (reject, e^x>0)
..
e^x=3/2
xlne=ln(3/2)
x=ln(3/2) (ans)
..
I don't know how they got answer you found, ln(3)/2

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