1)21 = 7 * 3
18 = 2 * 3 * 3 = 2 * 3(кв)
НОК (21 и 18) = 7 * 2 * 3² = 14 * 9 = 126
2)24 = 3 * 2³
32 = 7 * 2(кв)
НОК (24 и 32) = 3 * 7 * 2(в 3-ей степени)= 21 * 8 = 168
3)16 = 2(в 4-ой степени)
20 = 5 * 2(кв)
НОК (16 и 20) = 2⁴ * 5 = 16 * 5 = 80
4)20 = 5 * 2(кв)
35 = 5 * 7
НОК (20 и 35) = 5 * 7 * 2 (кв)= 35 * 4 = 140
5)75 = 3 * 5(кв)
90 = 2 * 3 * 3 * 5 = 2 * 5 * 3(кв)
НОК (75 и 90) = 5 (кв)* 3(кв)* 2 = 25 * 9 * 2 = 450
6)6 = 2 * 3
13 = 13 * 1
НОК (6 и 13) = 6 * 13 = 78
7)14 = 2 * 7
18 = 2 * 2 * 3 = 2 (кв)* 3
НОК (14 и 18) = 2 (кв)* 7 * 3 = 4 * 21 = 84
8)28 = 7 * 2(кв)
42 = 7 * 2 * 3
НОК (28 и 42) = 7 * 2(кв) * 3 = 21 * 4 = 84
9)21 = 7 * 3
33 = 3 * 11
НОК (21 и 33) = 7 * 3 * 11 = 7 * 33 = 231
10)12 = 2 * 2 * 3 = 2 (кв)* 3
30 = 2 * 3 * 5
75 = 3 * 5(кв)
НОК (12, 30 и 75) = 2(кв)* 3 * 5(кв) = 4 * 3 * 25 = 12 * 25 = 300
11) 15 = 3 * 5
42 = 7 * 2 * 3
105 = 3 * 5 * 7
НОК (15, 42 и 105) = 3 * 5 * 2 * 7 = 210
12) 21 = 3 * 7
28 = 2(кв) * 7
35 = 5 * 7
НОК (21,28 и 42) = 7 * 3 * 5 * 2(кв) = 420