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Find the 43rd term of the sequence 13.1,3.1,-6.9,-16.9,

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Arithmetic sequence.
a₁ = 13.1; a₂ = 3.1

d = a₂ - a₁ = 3.1 - 13.1 = -10
a₄₃ = a₁ + d(n-1) = 13.1 - 10(43-1) = 13.1 - 10 * 42 = 13.1 - 420 = -406.9

Answer: -406.9

User Allan Nienhuis
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