Question

Which of the following choices is the common difference between the terms of this arithmetic sequence? 55, 50, 45, 40, 35, ... A. -10 B. 55 C. 5 D. -5 E. 10

Answer 1

the answer is D...because in the sequence they subtract 5 in each number

Answer 2

55, 50, 45, 40, 35,…
- 5 - 5 - 5 - 5

The common difference between the terms of the arithmetic sequence is -5, making the answer D.

a(n) = a₁ + d(n - 1)
a(n) = 55 - 5(n - 1)
a(n) = 55 - 5(n) + 5(1)
a(n) = 55 - 5n + 5
a(n) = -5n + 55 + 5
a(n) = -5n + 60