Question

The first term of an arithmetic sequence is –12 and the ninth

Answer 1

Answer:

d = $\frac{7}{2}$

Step-by-step explanation:

The nth term of an arithmetic sequence is

$a_{n}$ = a₁ + (n - 1)d

where a₁ is the first term and d the common difference

Given a₉ = 16 , then

- 12 + 8d = 16 ( add 12 to both sides )

8d = 28 ( divide both sides by 8 )

d = $\frac{28}{8}$ = $\frac{7}{2}$