∵1=1-
+1 2
-1 2
+1 3
-1 3
+…+1 4
-1 9
+1 10
1 10
=(1-
)+(1 2
-1 2
)+(1 3
-1 3
)+…+(1 4
-1 9
)+1 10
1 10
=
+1 2
+1 6
+1 12
+1 20
+1 30
+1 42
+1 56
+1 72
+1 90
.1 10
∴这10个数可以是:2、6、10、12、20、30、42、56、72、90(答案不唯一).
用错位相减的方法如:1/2+1/6=1-1/2+1/2-1/3
按此推理,把数消掉,只剩1,可知1/2+1/6+1/12+1/20+1/30+1/42+1/56+1/72+1/90+1/10=1
所以这十个数是:2、6、12、20、30、42、56、72、90、10