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 (a₁ + aₙ) / 2
where a₁ is the first term and aₙ is the last term.
252 = n (-16 + 72) / 2
n = 9
The nth term of an arithmetic sequence is:
aₙ = a₁ + d (n−1)
where d is the common difference.
72 = -16 + d (9−1)
d = 11
There are 9 terms, and the common difference is 11.
