Consider the indefinite integral x5(x6+7)6 dx\displaystyle \int\frac{{x}^{{5}}}{{\left({x}^{{6}}+{7}\right)}^{{6}}}\ {\left.{d}{x}\right.}:

This can be transformed into a basic integral by letting

u=\displaystyle {u}=   and

du=\displaystyle {d}{u}=dx\displaystyle {\left.{d}{x}\right.}  

Performing the substitution yields the integral

\displaystyle \intdu\displaystyle {d}{u}