Question

Find the missing value of x in the arithmetic sequence below. 5, 1, x, -7, -11

Answer 1

x = - 3

Explanation:

the common difference d of an arithmetic sequence is

a₂ - a₁ = a₃ - a₂ , that is

1 - 5 = x - 1

- 4 = x - 1 ( add 1 to both sides )

- 3 = x

Answer 2

-3

Explanation:

Reason = -4

then

5

5-4 = 1

1-4 = -3

-3-4 = -7

-7-4 = -11