How do you find the term n=81, given the arithmetic sequence #a_1=20# and d=4? Precalculus Sequences Arithmetic Sequences 1 Answer Shwetank Mauria Nov 4, 2016 #81^(st)# term of the arithmetic sequence is #340#. Explanation: #n^(th)# term of an arithmetic sequence, whose first term is #a_1# and common difference is #d# is #a_1+(n-1)xxd# As we have #a_1=20# and common difference is #d=4# #81^(st)# term of the arithmetic sequence is #20+(81-1)xx4=20+80xx4=20+320=340# Answer link Related questions What is a descending arithmetic sequence? What is an arithmetic sequence? How do I find the first term of an arithmetic sequence? How do I find the indicated term of an arithmetic sequence? How do I find the #n#th term of an arithmetic sequence? What is an example of an arithmetic sequence? How do I find the common difference of an arithmetic sequence? How do I find the common difference of the arithmetic sequence 2, 5, 8, 11,...? How do I find the common difference of the arithmetic sequence 5, 9, 13, 17,...? What is the common difference of the arithmetic sequence 5, 4.5, 4, 3.5,...? See all questions in Arithmetic Sequences Impact of this question 2116 views around the world You can reuse this answer Creative Commons License