\(a) 30 = 2 . 3 . 5 => Ư(30) = {1; 2; 3; 6; 10; 15; 30}.\)
\(b) 225 = 3 . 3 . 5 . 5 = 32. 52=> Ư(225) = {1; 3; 5; 9; 15; 25; 45; 75; 225}.\)
\(c) 210 = 2 . 3 . 5 . 7 => Ư(210) = {1; 2; 3; 5; 6; 7; 10; 14; 15; 21; 30; 35; 42; 70; 105; 210}.\)
\(d) 242 = 2 . 2 . 11 = 22. 11 => Ư(242) = {1; 2; 11; 22; 121; 242}.\)