The domain of

$\displaystyle {R}{\left({x}\right)}=\frac{{-{4}{x}+{36}}}{{{x}^{{3}}-{16}{x}^{{2}}+{63}{x}}}$

is all real numbers except (in order from smallest to largest) $\displaystyle {x}=$ , $\displaystyle {x}=$ , and $\displaystyle {x}=$ .