a)0,(61)=61/99
14,(12)=(1412-14)/99=1398/99=466/33
21,(3)=(213-21)/9=192/9=64/3
2,(125)=(2125-2)/999=2123/999
0,(3024)=3023/9999
1990,(36)=(199036-1990)/99=197046/99=65682/33=21894/11
b)1,1(3)=(113-11)/90=102/90=34/30=17/15
22,5(12)=(22512-225)/990=22287/990=7429/330
10,14(5)=(10145-1014)/900=9131/990
0,236(4)=(2364-236)/9000=2128/9000=1064/4500=532/2250=266/1125
1,057(23)=(105723-1057)/99000=104666/99000=52333/49500
0,5(368)=(5368-5)/9990=5363/9990