The second term of an arithmetic sequence is –39. the rule mc014-1.jpg can be used to find the next term of the sequence. what is the explicit rule for the arithmetic sequence?

A 2 = -39
a 2 = a 1 + 12
- 39 = a 1 + 12
a 1 = - 39 - 12
a 1 = - 51 ( first term )
The common difference is : d = 12
The explicit rule for the arithmetic sequence:
a n = a1 + ( n - 1 ) d
a n = -51 + ( n - 1 ) · 12 

Ithink it is 7. 16