1)
480 = 2 * 2 * 2 * 2 * 2 * 3 * 5;
216 = 2 * 2 * 2* 3 * 3 * 3;
144 = 2 * 2 * 2 * 2 * 3 * 3,
НОК (480, 216, 144) = (2 * 2 * 2 * 3) * 2 * 2 * 3 * 3 * 5 = 4320,
2)
280 = 2 * 2 * 2 * 5 * 7;
140 = 2 * 2 * 5 * 7;
224 = 2 * 2 * 2 * 2 * 2 * 7,
НОК (280, 140, 224) = (2 * 2) * 2 * 5 * 7 * 2 * 2 = 1120