Respuesta :

Answer:

C. 3

Step-by-step explanation:

[tex]6 = 2 \times 3 \\ \\ 21 = 3 \times 7 \\ \\ \because \: common \: factor = 3 \\ \\ \therefore \: gcf \: of \: 6 \: and \: 21 = 3[/tex]

Answer:

C. 3

Step-by-step explanation:

Prime Factorization of 6:  2 × 3

Prime Factorization of 21:  3 × 7

Common Factors of 6 and 21: 3

So the greatest common factor of 6 and 21 is 3, that is, GCF of 6 and 21 is 3.