Can some one explain why I am getting this wrong

[viciousp]

Can some one explain why I am getting this wrong[SOLVED]

Homework Statement

Evaluate
$$\int ln(x+x^{2}) dx$$

Homework Equations

The Attempt at a Solution

I integrated by parts to get down to $$xln(x+x^{2})-\int \frac{(2x-1)}{x+1}$$ I set $$u=1+x$$ which led to $$du=1 dx$$ and $$x=u-1$$ after so evaluation I got down to $$-(\int 2 du -\int \frac{1}{u} du)$$ and after more substitution and evaluation I got down to $$xln(x+x^{2})+ln\left|1+x \right|-2-2x +C$$, but my book says that I should have only got -2x and not that extra -2

 

[viciousp]

Nevermind I figured it out

 

[snipez90]

Huh weird, this same problem was solved yesterday. Which book are you using for calculus if you don't mind me asking?

 

[viciousp]

Thomas Calculus, I still don't get how I messed up on substitution but I just long divided and got the answer

 

[rock.freak667]

You didn't need to use integration by parts though.