Respuesta :
Answer: -4
Step-by-step explanation:
13 - 9 = 4
9 - 5 = 4
so, we can see that it is decreasing by 4 each time.
Answer:
common difference is -4
Step-by-step explanation:
The common difference is the amount we add between terms
13 + d = 9
Subtract 13 from each side
13+d-13 = 9-13
d = -4
Check
9+d = 5
9 + -4 = 5
5= 5
This is true so the common difference is -4