Odpowiedź :
0,(5)=x /*10
5,(5)=10x
5,(5)-0,(5)=10x-x
5=9x
x=5/9
0,(12)=x
12,(12)=100x
12,(12)-0,(12)=100x-x
12=99x
x=12/99=4/33
5,67(68) =x
567,(68)=100x
56768,(68)=10000x
56768,(68)-567,(68)=10000x-100x
56201=9900x
x=56201/9900
5,(5)=10x
5,(5)-0,(5)=10x-x
5=9x
x=5/9
0,(12)=x
12,(12)=100x
12,(12)-0,(12)=100x-x
12=99x
x=12/99=4/33
5,67(68) =x
567,(68)=100x
56768,(68)=10000x
56768,(68)-567,(68)=10000x-100x
56201=9900x
x=56201/9900