Điền kí hiệu \( \in \) hoặc \( \notin \) vào ô vuông cho đúng :
\(\eqalign{
& a)\;4...ƯC\left( {12,18} \right) \cr
& b)\;6...ƯC\left( {12,18} \right) \cr
& c)\;2...ƯC\left( {4,6,8} \right) \cr
& d)\;4...ƯC\left( {4,6,8} \right) \cr
& e)\;80...BC\left( {20,30} \right) \cr
& g)\;60...BC\left( {20,30} \right) \cr
& h)\;12...BC\left( {4,6,8} \right) \cr
& i)\;24...BC\left( {4,6,8} \right). \cr} \)
\(\eqalign{ & a)\;4 \notin ƯC\left( {12,18} \right) \cr & b)\;6 \in ƯC\left( {12,18} \right) \cr & c)\;2 \in ƯC\left( {4,6,8} \right) \cr & d)\;4 \notin ƯC\left( {4,6,8} \right) \cr & e)\;80 \notin BC\left( {20,30} \right) \cr & g)\;60 \in BC\left( {20,30} \right) \cr & h)\;12 \notin BC\left( {4,6,8} \right) \cr & i)\;24 \in BC\left( {4,6,8} \right). \cr} \)