Let x=0.3‾x = 0.\overline 3x=0.3. Then 10x=3.3‾10x = 3.\overline 310x=3.3; subtract: 9x=39x = 39x=3, so x=1/3x = 1/3x=1/3. For 0.ab‾0.\overline{ab}0.ab: multiply by 100.