12 = 2 * 2 * 3 * 1
21 = 3 * 7 * 1
42 = 2 * 3 * 7 * 1
НОК (21, 21 и 42) = 2 * 2 * 3 * 7 * 1= 84
150 = 2 * 3 * 5 * 5 * 1
315 = 3 * 3 * 5 * 7 * 1
НОК (150 и 315) = 3 * 3 * 2 * 5 * 5 * 7 * 1 = 3150
