Tell whether the sequence is arithmetic, geometric, or neither. Find the next three terms of the sequence. Type your answer in the blank to the left. A. neither; 7, -20, 61 B. geometric;7, -20, 61 C. arithmetic; D. geometric;
Given, r = {7, -20, 61...} Find a relationship between the first three terms of the sequence: The difference between 7 and -20 is (−3)3=−27 The difference between -20 and 61 is (−3)4=81 Thus we can assume the next term of the sequence is 61+(−3)5=61−243=−182 If −182 is the next term of the sequence, then term following it is: −182+((−3)6=−182+729=549 And the term following 549 is 549+(−3)7=549−2187=−1638 In other words, the common difference between the terms is (−3)n+2 Which is neither arithmetic nor geometric