Answer:
2
Step-by-step explanation:
use your head
Answer:
c=72
Step-by-step explanation:
8
=
9
8
⋅
8
=
8
⋅
9
Answer: -216
Step-by-step explanation:
To solve the exercise you must use the formula shown below:

Where:

You should find 
The formula to find it is:

Where d is the difference between two consecutive terms.

Then:

Substitute it into the first formula. Therefore, you obtain:
