Answer:
Explanation:
For a sequence to be "arithmetic," there must be a common difference from one term to the next. 6,7,9,10,12... does not live up to this criterion:
from 6 to 7 is 1
from 7 to 9 is 2
from 9 to 10 is 1
from 10 to 12 is 2
If the sequence were 6, 7, 8, 9, 10, the sequence would be "arithmetic," with a common difference of 1.