Answer:
aₙ = 7 +3(n -1)
Explanation:
The numbers in the given sequence have a common difference, so this is an arithmetic sequence. The formula for the n-th term applies.
aₙ = a₁ +d(n -1)
Application
The first term is 7. The common difference is 10-7 = 3. Using the above formula for the n-th term, we find it to be ...
aₙ = 7 +3(n -1)
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Additional comment
This can be simplified to ...
aₙ = 3n +4