\[\boxed{\mathbf{260}.}\]
\[1)\ 91^{40} - 55^{35}\]
\[91\ :18 = 5\ (ост.\ 1) \rightarrow 91^{40}\ :\]
\[:18 = a\ (ост.\ 1);\]
\[55\ :18 = 3\ (ост.\ 1) \rightarrow 55^{35}\ :\]
\[:18 = b\ (ост.\ 1).\]
\[Если\ целые\ числа\ при\ делении\ \]
\[на\ натуральное\ число\ \]
\[дают\ равные\]
\[остатки,\ то\ разность\ этих\]
\[\ чисел\ кратна\ данному\ числу.\]
\[91^{40} - 55^{35}\ \vdots 18.\]
\[2)\ 84^{20} + 101^{19}\]
\[84^{20} \equiv 16\ (mod\ 17);\]
\[101^{19} \equiv 16\ (mod\ 17):\]
\[84^{20} + 101^{19} \equiv 16^{20} +\]
\[+ 16^{19}(mod\ 17) \equiv 16^{19} \cdot\]
\[\cdot (16 + 1)\ (mod\ 17) \equiv\]
\[\equiv 16^{19} \cdot 17\ (mod\ 17) = 0.\]
\[84^{20} + 101^{19}\ \vdots 17.\]
\[3)\ (75 \cdot 39)^{10} + (94 \cdot 58)^{15} =\]
\[= 2925^{10} + 5452^{15}\]
\[2925 \equiv - 1\ (mod\ 19);\ \ \]
\[5452^{15} \equiv - 1\ (mod\ 19);\]
\[( - 1)^{10} + ( - 1)^{15} = - 1 + 1 = 0.\]
\[(75 \cdot 39)^{10} + (94 \cdot 58)^{15}\ \vdots 19.\]
\[4)\ 10^{327} + 56\]
\[10 \equiv - 1\ (mod\ 11);\ \]
\[\ 56 \equiv 1\ (mod\ 11);\]
\[( - 1)^{327} + 1 = - 1 + 1 = 0.\]
\[10^{327} + 56\ \vdots 11.\]
\[5)\ 4^{15} + 233\]
\[4 \equiv 1\ (mod\ 3);\ \ \]
\[233 \equiv - 1\ (mod\ 3);\]
\[1^{15} - 1 = 1 - 1 = 0;\]
\[4^{15} + 233\ \vdots 3.\]