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Find the 14th term of the arithmetic sequence -x-5, 6x - 7, 13x - 9,...

User Drakekin
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1 Answer

4 votes

Answer: a₁₄=90x-31

Explanation:

-x-5, 6x-7, 13x-9 ...

Hence,

a₁=-x-5

a₂=6x-7

a₃=13x-9

d=a₂-a₁

d=6x-7-(-x-5)

d=6x-7+x+5

d=7x-2

aₙ=a₁+d(n-1)

a₁₄=-x-5+(7x-2)(14-1)

a₁₄=-x-5+13(7x-2)

a₁₄=-x-5+91x-26

a₁₄=90x-31

User Paul Beckingham
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