Name Date Class LESSON Practice A 12-3 Arithmetic Sequences and Series Determine whether the sequence is arithmetic. If it is, find the common difference. Then find the next term. If the sequence is not arithmetic, write not arithmetic. 1. 14, 23, 32, 41, 50, 59, 68, ... a. Find the differences between consecutive terms. b. If the sequence is arithmetic, write the common difference. c. If the sequence is arithmetic, add the common difference to the last term to get the next term. 2. 7.1, 10.6, 14.1, 17.6, 21.1, 24.6, ... a. If the sequence is arithmetic, write the common difference. b. If the sequence is arithmetic, find the next term. 3. 111, 99, 87, 75, 63, 51, 39, 27, 15, ... a. If the sequence is arithmetic, write the common difference. b. If the sequence is arithmetic, find the next term. 4. 2, -4, 6, -8, 10, -12, 14, -16, 18, -20, ... a. If the sequence is arithmetic, write the common difference. b. If the sequence is arithmetic, find the next term. Find the 11th term of each arithmetic sequence. 5. 33, 29, 25, 21, 17, ... a. Find the common difference. b. Substitute the first term for a, and the common difference for d in the formula a, = a, + (n - 1)d. c. Simplify. 6. 10, 3, -4, -11, -18, ... 7. 2, 4, 2, 8, 10, 4 , ... Write the missing terms of each arithmetic sequence. 8. 8.2, _, _ _, 23, ... a. Use a, = a, + (n - 1)d to find d, the common difference. you b. Use the common difference and the formula to find a2, 23, and a4. 9. 9, _ _ _ 10 , ... 74 a. Identify the common difference. b. Use the common difference to find the missing terms. Holt Algebra 2 19 Copyright @ by Holt, Rinehart and Winston. All rights reserved