\[\boxed{\mathbf{1.}\mathbf{173}\mathbf{.\ ОК\ ГДЗ - домашка\ на\ }5}\]
Пояснение.
Решение.
\[A = \left\{ 1;3;9 \right\};\ \ B = \left\{ 1;2;4;8 \right\}\]
\[A \cup B = \left\{ 1;2;3;4;8;9 \right\};\]
\[A \cap B = \left\{ 1 \right\}.\]