Answer :

Times it by 100 so you get 39.39/100 and then take off 1/100 which is 0.39 so your answer is 39/99 which you can then cancel down to 13/33. Hope this helps :)
[tex]1)\ \ 0,39= \frac{39}{100}\\ \\2)\ \ 0,(39)=x\\ \\x=0,393939...\ /\cdot100\\100x=39,393939...\\ \\100x-x=39,393939...-0,393939...\\ \\99x=39\ /:99\\\\ x= \frac{39}{99} \\ \\x= \frac{39:3}{99:3} \\ \\x= \frac{13}{33} [/tex]