[tex]\displaystyle\int \left( u^6 - 2u^5 - u^3 + \cfrac{2}{7} \right)du\implies \cfrac{u^7}{7}-2\cdot \cfrac{u^6}{6}-\cfrac{u^4}{4}+\cfrac{2}{7}u \\\\[-0.35em] ~\dotfill\\\\ ~\hfill \cfrac{u^7}{7}- \cfrac{u^6}{3}-\cfrac{u^4}{4}+\cfrac{2u}{7}+C~\hfill[/tex]