\[\boxed{\mathbf{74}\mathbf{.}}\]
\[1)\ a^{\sqrt{2}} \bullet a^{1 - \sqrt{2}} = a^{\sqrt{2} + 1 - \sqrt{2}} =\]
\[= a^{1} = a\]
\[2)\ a^{\sqrt{3} - 1} \bullet a^{\sqrt{3} + 1} =\]
\[= a^{\sqrt{3} - 1 + \sqrt{3} + 1} = a^{2\sqrt{3}}\]
\[3)\ \left( b^{\sqrt{3}} \right)^{\sqrt{3}}:b^{2} = b^{\sqrt{3 \bullet 3}}\ :b^{2} =\]
\[= b^{\sqrt{3^{2}}}\ :b^{2} = b^{3}\ :b^{2} = b^{3 - 2} =\]
\[= b^{1} = b.\]