3. Write down the faclors for the following, and circle the commonfarios for each pair of numbers. a. 12 ? 24 b. 28 21 c. 15 18 d. 24 60 e. 18 81 81

For 12 and 24, the factors of 12 are 1, 2, 3, 4, 6, 12, and for 24, they are 1, 2, 3, 4, 6, 8, 12, 24. The common factors are 1, 2, 3, 4, 6, and 12! For 28 and 21, the factors of 28 are 1, 2, 4, 7, 14, 28, and for 21, they are 1, 3, 7, 21. The only common factor is 1 and 7! For 15 and 18, the factors of 15 are 1, 3, 5, 15, while for 18, they are 1, 2, 3, 6, 9, 18. The common factor here is just 1 and 3! For 24 and 60, the factors of 24 are 1, 2, 3, 4, 6, 8, 12, 24, and the factors of 60 are 1, 2, 3, 4, 5, 6, 10, 12, 15, 20, 30, 60. The common factors are 1, 2, 3, 4, 6, and 12! For 18 and 81, the factors of 18 are 1, 2, 3, 6, 9, 18, while the factors of 81 are 1, 3, 9, 27, 81. The common factors here are 1, 3, and 9!