What is the common difference between successive terms in the sequence?
9, 2.5, -4, -10.5, -17, …

Solution:

The given sequence is 9 , 2.5, -4 , -10.5, -17 ,...

So, common difference

d = a₁ - a₂

d = 2.5 - 9

⇒ d = -6.5

⇒ d = - 4 - 2.5 = -6.5

⇒ d = - 10.5 - (-4) = -6.5

⇒ d = -17 - (-10.5) = -6.5

Therefore, the common difference is d = -6.5

What is the common difference between successive terms in the sequence?
9, 2.5, -4, -10.5, -17, …

Summary:

The common difference between successive terms in the sequence 9, 2.5, -4, -10.5, -17, … is d = -6.5