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Find the 15th term of the arithmetic sequence 2x+2, 8x-3, 14x-8,...

1 Answer

2 votes

Answer:

a₁₅ = 86x - 68

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

Here a₁ = 2x + 2

d = a₂ - a₁ = 8x - 3 - 2x - 2 = 6x - 5 , then

a₁₅ = 2x + 2 + 14(6x - 5)

= 2x + 2 + 84x - 70

= 86x - 68