解:0.12111L(1为循环节)
=0.12+0.00111L
=0.12 + 0.111L/100
设a= 0.111L
则10a=1 .111L,即10a=1+ 0.111L=1+a
所以 10a-a=1
9a=1
a=1/9
所以: 0.12 + 0.111L/100
=0.12 + (1/9)/100
=0.12 + 1/900
=12/100 + 1/900
=108/900 + 1/900
=109/900
解:0.12111L(1为循环节)
=0.12+0.00111L
=0.12 + 0.111L/100
设a= 0.111L
则10a=1 .111L,即10a=1+ 0.111L=1+a
所以 10a-a=1
9a=1
a=1/9
所以: 0.12 + 0.111L/100
=0.12 + (1/9)/100
=0.12 + 1/900
=12/100 + 1/900
=108/900 + 1/900
=109/900