Depends on the subject. If it's knowledge based like history or Spanish then you just learn the stuff and you're done.
If it's skill based where you need to be able to apply the stuff on the syllabus like Maths or Physics then no. You need to practice skills like maths so would probably take more than a month... if you wanted to do well.
But I guess you'd have to work 10months*2years/4subjects = 5 times harder than anyone else... Yeah, there's probably not enough hours in a day for that to happen. It's probably impossible unless you have photographic memory or something...