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In an arithmetic sequence aₙ, a₁ + a₁1 = 2019. Find a₆.

a. 806
b. 809
c. 812
d. 815

1 Answer

4 votes

Final answer:

To find a₆ in an arithmetic sequence aₙ, where a₁ + a₁1 = 2019, we need to establish the formula for the nth term of the sequence. In this case, since the sum of the first two terms is 2019, we can write the equation 2a₁ + d = 2019.

Step-by-step explanation:

To find a₆ in an arithmetic sequence aₙ, where a₁ + a₁1 = 2019, we need to establish the formula for the nth term of the sequence.

In an arithmetic sequence, the nth term aₙ can be found using the formula:

aₙ = a₁ + (n-1)d

Where a₁ is the first term, n is the position of the term, and d is the common difference between terms.

In this case, since the sum of the first two terms is 2019, we can write:

a₁ + (a₁ + d) = 2019

Simplifying this equation, we get:

2a₁ + d = 2019

Now, we can substitute the value of a₁ using the formula for the nth term:

2(a₁) + d = 2019

a₁ + (n-1)d = 2019

Plugging in n = 6, we can solve for a₆:

a₁ + (6-1)d = 2019

a₁ + 5d = 2019

Since the specific values of a₁ and d are not given, we cannot determine the exact value of a₆. Therefore, the answer cannot be determined from the information provided.

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