Question

First term of an arithmetic sequence is 5 and common difference is 3. find the algebraic expression and 20th term?


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Answer 1

An arithmetic sequence is a sequence where each term increases by adding/subtracting some constant k. This is in contrast to a geometric sequence where each term increases by dividing/multiplying some constant k. Example: a1 = 25. a(n) = a(n-1) + 5.To find the number of terms in an arithmetic sequence, divide the common difference into the difference between the last and first terms, and then add 1.