Aqa buss1 aqa exam monday omgomgomg

Hey!.So I'm self doing this unit and unit 2 and having major problems with the essays. Really it's just number 2 the 10 marker and the 15 markers. Basically is it correct or acceptable to keep on getting somthing OUT OF CONTEXT i.e. from the text book and then relating it to the case study..i.e. if a question said analyse why income budget may not be predicted accuratley and I said somthing like it may be difficult to predict the predict unfroseen changes in the market which in turn could mean hear market research would have been wrong etc etc etc...That's what I've been doing but the markscheme answers always come out with answers that are directly derived soley from the case study...I'm asking can I instead of that derive text book 'answers' then relate it to the case study instead?