x = 0,545454...
100x = 54,545454...
100x = 54 + 0,545454
100x = 54 + x
99x = 54
x = 54/99
x = 6/11
-----
x = 19,787878...
x - 19 = 0,78787878...
y = 0,78787878...
100y = 78,787878...
100y = 78 + 0,787878...
100y = 78 + y
99y = 78
y = 78/99
y = 26/33
0,78787878... = 26/33
19,787878... = 19 + 0,787878...
19,787878... = 19 + (78/99)
19,787878... = (1881/99) + (78/99)
19,787878... = 1959/99
19,787878... = 653/33
-----
z = 0,123123123...
1000z = 123,123123123...
1000z = 123 + 0,123123123...
1000z = 123 + z
999z = 123
z = 123/999
z = 41/333
-----
Sauf distraction.