SOLUTION: Can I please get help in solving this question. Thanks :) i)e^2x - 5e^x + 6 = 0

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Question 1106425: Can I please get help in solving this question. Thanks :)
i)e^2x - 5e^x + 6 = 0

Answer by ikleyn(52786) About Me  (Show Source):
You can put this solution on YOUR website!
.
Can I please get help in solving this highlight%28cross%28question%29%29 equation. Thanks :)
e^2x - 5e^x + 6 = 0
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        It is 129-th time as we, the tutors, ask you DO NOT USE words "solve question". There is no such term in English.

                Simply say "solve equation".     T h a n k s.


Standard way is introducing new variable y = e%5Ex. 

Then the equation takes the form


y^2 - 5x + 6 = 0.


Factor left side:


(y-2)*(y-3) = 0.


There are 2 solutions:  y = 2  and  y = 3.


1)  y = 2 ====>  e%5Ex = 2  ====>  x = ln(2).


2)  y = 3  ====>  e%5Ex = 3  ====>  x = ln(3).


Answer.  There are two solutions:  x = ln(2)   and   x = ln(3).


Check.   1)  x = ln(2):  e%5E%282x%29++-++5e%5Ex++%2B+6 = e%5E%282%2Aln%282%29%29+-5%2Ae%5Eln%282%29+%2B+6 = 2%5E2+-+5%2A2+%2B+6 = 4 - 10 + 6 = 0.  ! Correct !


         2)  x = ln(3):  e%5E%282x%29++-++5e%5Ex++%2B+6 = e%5E%282%2Aln%283%29%29+-5%2Ae%5Eln%283%29+%2B+6 = 3%5E2+-+5%2A3+%2B+6 = 9 - 15 + 6 = 0.  ! Correct !

Solved.