If m is a non - zero number and \( \int \frac {x^{5m-1}+2x^{4m-1}}{(x^{2m}+x^m+1)^3}dx=f(x)+c \), then f(x) is :
1
\( \frac {x^{5m}}{2m(x^{2m}+x^m+1)^2} \)
2
\( \frac {x^{4m}}{2m(x^{2m}+x^m+1)^2} \)
3
\( \frac {2m(x^{5m}+x^{4m})}{(x^{2m}+x^m+1)^2} \)
4
\( \frac {(x^{5m}-x^{4m})}{2m(x^{2m}+x^m+1)^2} \)