the line over the 28 means the 28 repeats forever.
1.282828.... and so on
let x be the rational number 1.28...
we can use this trick:
100*1.282828....= 128.282828...
(the decimal 28 part repeats)
100x = 128.28...
next:
100x - x = 128.282828... - 1.282828...
the .282828... part will be subtracted away
99x = 127
divide both sides by 99 to get
x= 127/99
