Write a rule for the nth term of an arithmetic sequence that has two given terms of a2 = 6 and a6 = 30?

Science & Mathematics by Anonymous 2018-05-18 21:09:06

Social Science

2 answers

If there are 25 terms in this sequence, find the sum of the 25 terms. Please show your work so I can understand how you got your answer ! Thank you so much in advance for your help (:

Anonymous

Write a rule for the nth term of an arithmetic sequence that has two given terms of a2 = 6 and a6 = 30 If there are 25 terms in this sequence, find the sum of the 25 terms. 0, 6, 12, 18, 24, 30, ... an = 6 (n - 1) a25 = 144 S25 = 25(72) = 7200/4 = 1800
Anonymous

a + 5d = 30 a + d = 6 d = 24/4 = 6 and a = 0 The nth term is 6(n – 1) The 25th term is 144 The average value of a term is 72 Sum = average * number of terms = 72 *25 = 1800