Identify the common difference

1. Determine the common difference given the fourth term = 29 and the ninth term = 64.

2. Identify the common difference of the sequence 97, 86, 75, 64, ...

3.Determine the common difference given the general term an = -15n + 12.

4.Determine the common difference for the sequence -20, -27, -34, -41, -48, . . .

5. Determine the common difference given the general term an = 3n + 25.

6. Determine the common difference of the arithmetic sequence where the second term = -8 and the fourth term = -18.

7. Find the common difference: 1, 201, 401, 601, ...

8. Determine the common difference of the sequence 11, ___, 23, ___, 35, ___, . . .

9. Find the common difference: 29, 21, 13, 5, ... ​