英文数学题Ben cycles to a city at average speed X and returns at average speed Y.His average speedfor the whole trip is ( )

分类: 作业答案 • 2023-01-24 12:15:20

问题描述：

英文数学题Ben cycles to a city at average speed X and returns at average speed Y.His average speed
for the whole trip is ( )

答

2xy/(x+y)