8/25 4/5 5/8 29/20
7.666667 (你确定是20/3而不是3/20?即1.15) 1.25 8.33 2.86
(肯定又错了 应该是3又1/4 3.25)
0.9999999
=0.9 0.9*0.1 0.9*0.01 0.9*0.001 ......
=0.9*(1 10^-1 10^-2 10^-3 ......)
=0.9*(1/(1-0.1))
=9/9
=1
0.8989898
=0.89 0.89*0.01 0.89*0.0001 ......
=0.89*(1 10^-2 10^-4 ......)
=(89/100)*(1/(1-0.01))
=(89/100)*(100/99)
=89/99
哈哈哈哈哈我也不会