is it better do get around 80 in modern history which scales over +2, or get over 90 in business studies that scales -0.8 ? i'm asking this cause i have a couple of days to decide which one would be best for my UAI
Business Studies by far. Not having done Business Studies I don't know just how easy it is, but I doubt it'd be that much easier than modern. If you put in the effort I reckon 90 is pretty gettable for either subject.