Question

The problem is in the picture.

Answer 1

• an = 5 + 10(n -1)
• a7 = 65

Explanation:

The explicit formula for the n-th term of an arithmetic sequence is ...

an = a1 + d(n -1)

where a1 is the first term and d is the common difference.

The sequence of seat counts has a1=5 and d=10, so the explicit formula is ...

an = 5 +10(n -1)

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The 7th term is ...

a7 = 5 +10(7 -1) = 65