Posted by **Seth** on Thursday, April 4, 2013 at 1:20am.

Isolve for x: ln(x^2-6x-16)= 0 . help me beacuse I do not have the idea to work it out.

- Please help me here!!! Maths -
**Seth**, Thursday, April 4, 2013 at 1:23am
Solve for the value of x: ln(x^2-6x-16)=5. Please help me work it out because I do not have an idea in work it out.

- Please help me here!!! Maths -
**Sunny**, Thursday, April 4, 2013 at 1:31am
(x^2-6x-15)=e^5

e^5 is approximately 148.41

so x^2-6x=148.41-15

x^2-6x = 133.41

x-6x = sqrt(133.41)

-5x = 11.55

x = 11.55/-5

x = 2.31

- no - Please help me here!!! Maths -
**Reiny**, Thursday, April 4, 2013 at 7:37am
unfortunately Sunny made several errors,

Try to sub in x = 2.31, it does not work

form his/hers : (x^2-6x-16)=e^5 ---- Sunny had -15

x^2 - 6x = 148.413 + 16

complete the square by adding 9 to both sides

x^2 - 6x + 9 = 148.413+16+9 = 173.413

(x-3)^2 = 173.413

x-3 = ±√173.413 = ± 13.1686

x = 3 ± 13.1686

x = 16.1686 or x = -10.1686

both work when subbed into the original equation

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