kamishacannon1109 kamishacannon1109 11-03-2024 Mathematics contestada Let a₁,a₂,…,a₂₁ be an AP such that ²⁰∑ₙ₌₁ 1/aₙaₙ₊₁=4/9. if the sum of this AP is 189, then a₆a₁₆ is equal to : A. 36B. 48C. 72D. 57