$\begin{array}{1 1}(1)\large\frac{-x^5}{(x^5+x^3+1)^2}+C \\ (2)\large\frac{-x^5}{2(x^5+x^3+1)^3}+C \\(3) \large\frac{x^5}{2(x^5+x^3+1)^3}+C \\ \large\frac{-x^{10}}{2(x^5+x^3+1)^2}+C \end{array} $