Find the common difference of the arithmetic
sequence 13,9,5,

-4

Step-by-step explanation:

13 - 9 = 4

9 - 5 = 4

so, we can see that it is decreasing by 4 each time.

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

do you have the measurements?