For the integral 26e4x8dx\displaystyle {\int_{{{2}}}^{{{6}}}}{e}^{{{4}{x}-{8}}}{\left.{d}{x}\right.}, if we use the substitution u=4x8\displaystyle {u}={4}{x}-{8}, what will be the new integral?

ab\displaystyle {\int_{{a}}^{{b}}}   du\displaystyle {d}{u}

Where a=\displaystyle {a}=  

And b=\displaystyle {b}=