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## Answers

First, find the common difference between the consecutive terms.

a₁=38 a₂=28 a₃=18 a₄=8

a₂ - a₁ = 28 - 38 =

**-10**

a₃ - a₂ = 18 - 28 = -

**10**

a₄ - a₃ = 8 - 18 =

**-10**

d = -10 a₁=38

General rule/formula: an = a₁ + (n-1) (d)

d = -10 a₁=38

Rule (formula) for the given sequence 38, 28, 18, 8

an = 38 + (n-1)(-10)

an = 38 -10n + 10

an = -10n + 38 + 10

an = -10n + 48

**ANSWER:**= -10n + 48

To check:

a₁ = 38

a₁ = -10(1) + 48

a₁ = -10 + 48

a₁ = 38 (True)

a₂ = 28

a₂ = -10(2) + 48

a₂ = -20 + 48

a₂ = 28 (True)

a₃ = 18

a₃ = -10(3) + 48

a₃ = -30 + 48

a₃ = 18

You can do the checking for the last term, a₄.