\(\sqrt{81.16.169}=\sqrt{81}.\sqrt{16}.\sqrt{169}=9.4.13=468\)
\(\sqrt{10}.\sqrt{810}=\sqrt{10.10}.\sqrt{81}=10.9=90\)
\(\sqrt{64}.\sqrt{81.100}-\sqrt{64}.\sqrt{196.16}=\sqrt{64}\left(\sqrt{81}.\sqrt{100}-\sqrt{196}.\sqrt{16}\right)=8.\left(9.10-14.4\right)=8.34=272\)