Question

What is the common difference for this arithmetic sequence?

45, 39, 33, 27, 21, ...
A. 45
B. –6
C. 6
D. 39

Answer 1

B. -6
The numbers in the equation are decreasing meaning that the common difference must be a negative number.

Answer 2

-6

Explanation:

To find the common difference, subtract a number from the next number.

39 - 45 = -6

You can use any two consecutive terms. The result will be the same.

For example, 21 - 27 = -6

Answer: -6