Question

Determine if the sequence is arithmetic. If it is, find the common difference and create an explicit formula. Simplify the formula -3,-23,-43,-63

Answer 1

Below

Explanation:

Each term differs from the one prvious to it by a constant amount = -20

so it is arithmetic and d = -20

the formula would then be

an = -3 + (n-1) d since d = -20 this becomes an = -3 - 20(n-1)

an = -3 - 20n + 20

an = 17 - 20 n simplified.