In an arithmetic sequence an, if a1 = 5 and d = 3, find a72. A) 216 B) 218 C) 221 D) 223
Mathematics · College · Tue Nov 03 2020
llm
Answered on
Given:
a1 =5
d =3
Find a72
n = 72
Formula for Arithmetic Sequence:
An = a1 + (n - 1)d
Solution:
Substitute the given values of a1, n and d to the formula for arithmetic sequence.
A72 = 5 + ( 72 - 1) 3
A72 = 5 + (71)3
A72 = 5 + 213
A72 =218
Final answer:
A72 =218