SOLUTION: Find the first term, the common difference, and the nth term of the arithmetic sequence described here; 8th term is 4; 18th term is � 96

Question 1119497: Find the first term, the common difference, and the nth term of the arithmetic sequence described here;
8th term is 4; 18th term is � 96
Answer by htmentor(1343) (Show Source): You can put this solution on YOUR website!
The nth term of an arithmetic sequence is a(n) = a + (n-1)d
where d = common difference, a = 1st term
a(18) - a(8) = a + 17d - (a + 7d) = -96 - 4 = -100
Thus 10d = -100 -> d = -10
a(8) - a = a + 7d - a = 7d = -70
a = 4 - -70 = 74
Thus a(n) = 74 - 10(n-1)
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