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lnX+ln(x+2)=3

Guest Apr 21, 2017
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+3

Ln (x)  + Ln (x + 2)  = 3

 

And we can write

 

Ln  [ x ( x + 2) ]  = 3

 

This says that

 

e^3  = x ( x + 2)

e^3  = x^2 + 2x        rearrange

x^2 + 2x  - e^3  =  0

 

Using the quadratic formula, we have that  

 

x =  -1 -  √ [ 1 + e^3 ]     reject this  as it makes the logs undefned

or

x  =  -1 + √ [ 1 + e^3 ]    accept

 

 

cool cool cool

CPhill  Apr 21, 2017

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