The easiest way to figure this out is to get the factors of 8 and see if they are factors of 105. Factors of 8: 8, 4, 2, 1 Now check, 105/8 = 13.125 (not a factor) 105/4 = 26.25 (not a factor) 105/2 = 52.5 (not a factor) 105/1 = 105 (is a factor) So the common factor of 8 and 105 is 1.

1 and 105 are a factor pair of 105 since 1 x 105= 105 3 and 35 are a factor pair of 105 since 3 x 35= 105 5 and 21 are a factor pair of 105 since 5 x 21= 105 7 and 15 are a factor pair of 105 since 7 x 15= 105

The factor pairs of 210 are: 1 and 210, 2 and 105, 3 and 70, 5 and 42, 6 and 35, 7 and 30, 10 and 21, and 14 and 15. The factor pairs of 63 are: 1 and 63, 3 and 21, and 7 and 9.