4) Use prime factorisation to find the Hcf a) 28 and 32 b) 45 and 36
Answers
Answer:
a.hcf of 28 and 32 is 4
b.hcf of 45 and 36 is 9
Step-by-step explanation:
a) Methods to Find HCF of 28 and 32
Let's look at the different methods for finding the HCF of 28 and 32.
HCF of 28 and 32 by Listing Common Factors
Factors of 28: 1, 2, 4, 7, 14, 28
Factors of 32: 1, 2, 4, 8, 16, 32
There are 3 common factors of 28 and 32, that are 1, 2, and 4. Therefore, the highest common factor of 28 and 32 is 4.
HCF of 28 and 32 is (2 × 2 × 7) and (2 × 2 × 2 × 2 × 2) respectively. As visible, 28 and 32 have common prime factors. Hence, the HCF of 28 and 32 is 2 × 2 = 4.
b) HCF of 35 and 45 by Listing Common Factors
Factors of 35: 1, 5, 7, 35
Factors of 45: 1, 3, 5, 9, 15, 45
There are 2 common factors of 35 and 45, that are 1 and 5. Therefore, the Highest common factor of 35 and 45 is 5.