integrate x+5/(x^2+10x+26)

I have a feeling that you meant

integrate (x+5)/(x^2+10x+26)

I noticed that it would fit the pattern of ln(...)
since the derivative of the denominator shows up as a multiple in the numerator
lets doctor it up

(x+5)/(x^2+10x+26)
(1/2) (2x+10)/(x^2 + 10x + 26)

and the integral of that is
(1/2) ln(x^2 + 10x + 26) + C

if you did mean it the way you typed, it will be very messy.
I would try something like partial fractions, but the bottom does not factor, so it would involve some nasty radicals.