How do you find an equation that describes the sequence #3, 8, 13, 18,...# and find the 70th term? Precalculus Sequences Arithmetic Sequences 1 Answer sankarankalyanam Mar 17, 2018 #color (green)(70^(th) "term" # #color(green)( a_70 = 348# Explanation: #a_1 = 3# First to find common difference #d#. #d = a_2 - a_1 = a_3 - a_2 = a_4 - a_3 = 5# #a_n = a_1 + (n-1) * d# Therefore #a_70 = a_1 + (70 -1 ) * d = 3 + 69 * 5 = 348# 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 3342 views around the world You can reuse this answer Creative Commons License