Question

The first term of an arithmetic sequence is -5, and the tenth term is 13. Find the common difference. A.) 2 B.) 1.8 C.) 8/9

Answer 1

A

d = 2

Explanation:

Formula

l = a + (n - 1)d

Givens

n = 10

a = - 5

l = 13

Solution

13 = - 5 + (10 - 1)d Substitute

13+5 = -5+5 + 9d Add 5 to both sides

18 = 9d Divide by 9

18/9 = 9/d

d = 2