Answer
\[ = {x^9} - {x^7} + C\]
Work Step by Step
\[\begin{gathered}
\int_{}^{} {\,\left( {9{x^8} - 7{x^6}} \right)\,dx} \hfill \\
\hfill \\
use\,\,\int_{}^{} {{x^n}dx} = \frac{{{x^{n + 1}}}}{{n + 1}} + C \hfill \\
\hfill \\
then \hfill \\
\hfill \\
= \frac{{9{x^9}}}{9} - \frac{{7{x^7}}}{7} + C \hfill \\
\hfill \\
simplify \hfill \\
\hfill \\
= {x^9} - {x^7} + C \hfill \\
\hfill \\
\end{gathered} \]
