Answered

Consider the arithmetic sequence presented in the table below.




n 5 71

an 74 1,460



Hint: an = a1 + d(n − 1), where a1 is the first term and d is the common difference.


Part A: What is the first term, a1, of the sequence?


Part B: What is the general term equation, an, for this sequence?


Part C: What is the value of the 13th term of this sequence?

Verified Answer :

texaschic101

a5 and a71 are 66 places apart
a71 = a5 + 66d
1460 = 74 + 66d
1460 - 74 = 66d
1386 = 66d
1386/66= d
21= d

a5 = a + (5-1)21
74 = a + 4 21
74 = a + 84
74 - 84 = a
-10 = a <=== first term

general term equation : an = -10 + (n-1) 21

a13 = -10 + (13 - 1) 21
a13 = -10 + 12*21
a13 = -10 + 252
a13 = 242




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