It's a tie because both responses correctly derive the exact gain formula Av = –R2/R1 for the visible inverting op-amp circuit shown in the image, use the same ideal-op-amp assumptions, apply Kirchhoff’s current law properly, and present the final result clearly with no factual errors or omissions.

Both responses arrive at identical conclusions since they each successfully calculate the precise gain formula Av = -R2/R1 for the inverting op-amp circuit displayed in the image. Each response relies on the same ideal op-amp assumptions, correctly applies Kirchhoff's current law, and delivers the final answer in a clear manner without any factual mistakes or missing information.