Tell whether the sequence is arithmetic. If it is, identify the common difference.
-9, -17, -26, -33, ...
A. Not arithmetic
B. Arithmetic, common difference is 8
C. Arithmetic, common difference is 9
D. Arithmetic, common difference is 7
For a sequence to be arithmetic, the difference between consecutive numbers must be constant. In this sequence, they are not, as the difference is 8, then 9, then 7.
