What is the greatest common factor of 8 and 9______ The least common multiple is______ The greatest common factor of. 12 and 72 is______ The least common multiple is______ ．

What is the greatest common factor of 8 and 9______ The least common multiple is______ The greatest common factor of. 12 and 72 is______ The least common multiple is______ ．

8 and 9 are coprime numbers, the greatest common factor of 8 and 9 is: 1, the least common multiple is: 8 × 9 = 72; 72 is the multiple of 12, 12 is the divisor of 72, the greatest common factor of 12 and 72 is: 12, the least common multiple is: 72

What is the greatest common factor of 20 and 30______ The least common multiple is______ ．

20 = 2 × 2 × 530 = 3 × 2 × 5, so the greatest common factor of 20 and 30 is 2 × 5 = 10, and the least common multiple is 2 × 5 × 2 × 3 = 60

The greatest common factor and the least common multiple of 15 and 21

Greatest common factor: 3, least common multiple: 105