# Thread: problem evaluating this integral

1. ## problem evaluating this integral

I worked through this integral using partial fractions, but I cannot for the life of me evaluate it. At least, my answer is not what webassign wants. I think I am not putting my logs together correctly. Anyway, can someone please evaluate this and show me final steps of combining logs, etc.

Original problem:

$\int\limits^{9}_{7} \frac{x^3-5x^2-25}{x^3-5x^2} dx$

Here is my integral that I got using partial fractions, but that I cannot get my correct asnwer when I evaluate at the limits (I am assuming of course that I have the correct integral here):

$= \left[x + ln |x| - \frac{5}{x} - ln|x-5|\right] _{7}^{9}$

Thanks much!

2. Originally Posted by mollymcf2009
I worked through this integral using partial fractions, but I cannot for the life of me evaluate it. At least, my answer is not what webassign wants. I think I am not putting my logs together correctly. Anyway, can someone please evaluate this and show me final steps of combining logs, etc.

Original problem:

$\int\limits^{9}_{7} \frac{x^3-5x^2-25}{x^3-5x^2} dx$

Here is my integral that I got using partial fractions, but that I cannot get my correct asnwer when I evaluate at the limits (I am assuming of course that I have the correct integral here):

$= \left[x + ln |x| - \frac{5}{x} - ln|x-5|\right] _{7}^{9}$

Thanks much!
that integral is correct. so if you have a problem, it is from plugging in the limits, which is just arithmetic. just redo it.