Evaluate the integral
x5(x68)42dx,\displaystyle \int{x}^{{5}}{\left({x}^{{6}}-{8}\right)}^{{{42}}}{\left.{d}{x}\right.},
by making the substitution u=x68\displaystyle {u}={x}^{{6}}-{8}.

  + C

NOTE: Your answer should be in terms of x\displaystyle {x} and not u\displaystyle {u}.