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

9, 2.5, –4, –10.5, –17,

Hello!

The answer to your question is -6.5

:)

The common difference would be -6.5

Step-by-step explanation:

Given sequence,

9, 2.5, -4, -10.5, -17, ...

Since,

2.5 - 9 =  -4 - 2.5 = -10.5 + 4 = -17+10.5 ... = -6.5

Thus, 9, 2.5, -4, -10.5, -17, ... is an AP,

In an AP the difference between any two consecutive terms is called the common difference.

Hence, the common difference would be -6.5