Question

The first term of an arithmetic sequence is -5, and the tenth term is 13. Find the common difference.

02
01.8
O
618

Answer 1

d = 2

Explanation:

the nth term of an arithmetic sequence is

`a_(n)` = a₁ + (n - 1)d

a₁ is the first term , d the common difference , n the term number

given a₁ = - 5 and a₁₀ = 13 , then

a₁ + 9d = 13 ( substitute a₁ = - 5 )

- 5 + 9d = 13 ( add 5 to both sides )

9d = 18 ( divide both sides by 9 )

d = 2

the common difference d = 2