\[\boxed{\mathbf{499}.}\]
\[1)\ \sqrt[3]{10}\text{\ \ }и\ \ \sqrt[5]{20};\]
\[\sqrt[3]{10} = \sqrt[{3 \bullet 5}]{10^{5}} = \sqrt[15]{100\ 000};\]
\[\sqrt[5]{20} = \sqrt[{5 \bullet 3}]{20^{3}} = \sqrt[15]{8000};\]
\[100\ 000 > 8000;\]
\[\sqrt[15]{100\ 000} > \sqrt[15]{8000};\]
\[Ответ:\ \ \sqrt[3]{10} > \sqrt[5]{20}.\]
\[2)\ \sqrt[3]{5}\text{\ \ }и\ \ \sqrt[4]{7};\]
\[\sqrt[3]{5} = \sqrt[{4 \bullet 3}]{5^{4}} = \sqrt[12]{625};\]
\[\sqrt[4]{7} = \sqrt[{3 \bullet 4}]{7^{3}} = \sqrt[12]{343};\]
\[625 > 343;\]
\[\sqrt[12]{625} > \sqrt[12]{343};\]
\[Ответ:\ \ \sqrt[3]{5} > \sqrt[4]{7}.\]
\[3)\ \sqrt{17}\text{\ \ }и\ \ \sqrt[3]{28};\]
\[\sqrt{17} = \sqrt[{2 \bullet 3}]{17^{3}} = \sqrt[6]{4913};\]
\[\sqrt[3]{28} = \sqrt[{3 \bullet 2}]{28^{2}} = \sqrt[6]{784};\]
\[4913 > 784;\]
\[\sqrt[6]{4913} > \sqrt[6]{784};\]
\[Ответ:\ \ \sqrt{17} > \sqrt[3]{28}.\]
\[4)\ \sqrt[4]{13}\text{\ \ }и\ \ \sqrt[5]{23};\ \]
\[\sqrt[4]{13} = \sqrt[{4 \bullet 5}]{13^{5}} = \sqrt[20]{371\ 293};\]
\[\sqrt[5]{23} = \sqrt[{5 \bullet 4}]{23^{4}} = \sqrt[20]{279\ 841};\]
\[371\ 293 > 279\ 841;\]
\[Ответ:\ \ \sqrt[4]{13} > \sqrt[5]{23}.\]