Question

the factor tree for 60 has all of the factors in the factor trees for 15 and 30, but not 45. explain why this is true

Answer 1

45 is not a factor because you can't multiply anything with 45 to get 60: however, you can multiple 15 by a number and 30 by a number and get 60. 

Answer 2

15 and 30 are factors of 60 but 45 is not