1⼀2,1⼀3,1⼀4,1⼀5,···,1⼀90,1⼀91从中挑出10个数,加上正负数,它们的和等于—1

2025-12-17 05:37:21
推荐回答(1个)
回答1:

解:1/2+1/6+1/12+1/20+1/30+1/42+1/56+1/72+1/90+1/10=1