Question

Please help!!! If the first 4 terms of a geometric sequence are...

Answer 1

Answer:

c.) aₙ = 5 × 4ⁿ⁻¹

Explanation:

Geometric sequence: aₙ = a(r)ⁿ⁻¹

where 'a' resembles first term of a sequence, 'r' is the common difference.

Here sequence: 5, 20, 80, 320,...

First term (a) = 5

Common difference (d) = second term ÷ first term = 20 ÷ 5 = 4

Hence putting into equation: aₙ = 5(4)ⁿ⁻¹