MATH SOLVE

2 months ago

Q:
# Write the explicit formula for the arithmetic sequence. 2, -2, -6, -10, -14, ...A)an = 5 - 3nB)an = 6 - 4nC)an = 8 - 6nD)an = 10 - 8n

Accepted Solution

A:

Given from the question

arithmetic sequence

a₁ = 2

a₂ = -2

a₃ = -6

and so on..

First, find the difference of the sequence

d = a₂ - a₁

d = -2 - 2

d = -4

Second, built the formula

General formula

an = a₁ + d(n - 1)

plug the numbers to the general formula

an = a₁ + d(n - 1)

an = 2 -4(n - 1)

an = 2 - 4n + 4

an = 2 + 4 - 4n

an = 6 - 4n

The answer is option B

arithmetic sequence

a₁ = 2

a₂ = -2

a₃ = -6

and so on..

First, find the difference of the sequence

d = a₂ - a₁

d = -2 - 2

d = -4

Second, built the formula

General formula

an = a₁ + d(n - 1)

plug the numbers to the general formula

an = a₁ + d(n - 1)

an = 2 -4(n - 1)

an = 2 - 4n + 4

an = 2 + 4 - 4n

an = 6 - 4n

The answer is option B