Răspuns:
Explicație pas cu pas:1)Daca fractiile au acelas numitor....se pot scadea direct!Daca nu....atunci se introduc intregii in fractii si apoi se aduc la acelas numitor comun!......a)4,2/3-1,1/3=3,1/3sau 11/3......b)4,5/9-2,2/9=2,3/9,sau 21/9.......c)7,11/15-2,1/15=5,10/15.......d)9,1/20-9,7/20=-6/20,simplificat cu2=3/10.......e)4,5/6-1,1/6=3,2/3...............f)3,1/9-2,2/9=8/9.........g)7,10/15-2,1/15=5,9/15..........h)9,3/4-9,1/4=1/2....(2/4)..succes!!