Question on Indefinite Integration: $\int\frac{2x^{12}+5x^9}{\left(x^5+x^3+1\right)^3}\,\mathrm{d}x$ Give me some hints to start with this problem: $${\displaystyle\int}\dfrac{2x^{12}+5x^9}{\left(x^5+x^3+1\right)^3}\,\mathrm{d}x$$

Hint 
Take $x^5$ common from denominator so that it's cube it will come out as $15$ and take $x^{15}$ common from  the numerator. Put the remaining denominator as $t$ numerator becomes $dt$. Hope you can do the rest.
