Question

What is the common difference between successive terms in the sequence?

9, 2.5, –4, –10.5, –17

Answer 1

Answer:

2.5 = 9 + d, d = 2 - 9.5, d = - 6.5. We can check this answer: 2.5 + ( - 6.5 ) = - 4, - 4 +( - 6.5 ) = -10.5, - 10.5 + ( - 6.5 ) = - 17. Answer: The common difference is -