
Tabitha D. answered 01/22/20
Experienced Algebra Teacher Who Can Explain ‘Why’
The formula for a term in an arithmetic sequence is:
an = a1 + (n - 1)d
where an is the nth term, a1 is the first term, n is the number of terms, and d is the common difference. The common difference is the amount that is added or subtracted from term to term.
In this problem, we are given the first term and the 13th term. So let’s use the 13th term to find the common difference, d.
a13 = 28 + (13 - 1)d
100 = 28 + 12d
72 = 12d
d = 6
Now find the 37th term:
a37 = 28 + (37 - 1)(6)
a37 = 28 + (36)(6)
a37 = 28 + 216
a37 = 244
Zahra P.
thank you so much01/22/20