\[\boxed{\mathbf{491}.}\]
\[1)\ \left( 2^{\frac{5}{3}} \bullet 5^{- \frac{1}{3}} - 5^{\frac{5}{3}} \bullet 2^{- \frac{1}{3}} \right) \bullet \sqrt[3]{10} =\]
\[= \left( 2^{\frac{5}{3}} \bullet 5^{- \frac{1}{3}} - 5^{\frac{5}{3}} \bullet 2^{- \frac{1}{3}} \right) \bullet\]
\[\bullet (2 \bullet 5)^{\frac{1}{3}} =\]
\[= 2^{\frac{5}{3} + \frac{1}{3}} \bullet 5^{- \frac{1}{3} + \frac{1}{3}} - 5^{\frac{5}{3} + \frac{1}{3}} \bullet 2^{- \frac{1}{3} + \frac{1}{3}} =\]
\[= 2^{2} \bullet 5^{0} - 5^{2} \bullet 2^{0} =\]
\[= 4 - 25 = - 21;\]
\[2)\ \left( 5^{\frac{1}{4}}\ :2^{\frac{3}{4}} - 2^{\frac{1}{4}}\ :5^{\frac{3}{4}} \right) \bullet \sqrt[4]{1000} =\]
\[= \left( 5^{\frac{1}{4}} \bullet 2^{- \frac{3}{4}} - 2^{\frac{1}{4}} \bullet 5^{- \frac{3}{4}} \right) \bullet \sqrt[4]{10^{3}} =\]
\[= \left( 5^{\frac{1}{4}}\ \bullet 2^{- \frac{3}{4}} - 2^{\frac{1}{4}} \bullet 5^{- \frac{3}{4}} \right) \bullet\]
\[\bullet (5 \bullet 2)^{\frac{3}{4}} = 5^{\frac{1}{4} + \frac{3}{4}} \bullet 2^{- \frac{3}{4} + \frac{3}{4}} -\]
\[- 2^{\frac{1}{4} + \frac{3}{4}} \bullet 5^{- \frac{3}{4} + \frac{3}{4}} = \ \]
\[= 5^{1} \bullet 2^{0} - 2^{1} \bullet 5^{0} = 5 - 2 = 3.\]