Answer:
There are 9 terms, and the common difference is 11.
Step-by-step explanation:
The sum of the first n terms of an arithmetic sequence is:
S = n (aā + aā) / 2
where aā is the first term and aā is the last term.
252 = n (-16 + 72) / 2
n = 9
The nth term of an arithmetic sequence is:
aā = aā + d (nā1)
where d is the common difference.
72 = -16 + d (9ā1)
d = 11
There are 9 terms, and the common difference is 11.
