STUDY IS HARD

Haiz.. Today cant play the com.. because brother botting his GE acct.. so i have to do my homework then only can online.. I think that I didn't do my homework for about 2 weeks plus.. all accumulated and now it is hard to finish it all.. like just now i do 1 maths question and I find it hard to understand.. Prove that (A U B)' U B = (A - B)'.. I've stun and dont know how to do.. even simple physic and chemistry question I also can't answer.. I think i cant coop up with syllabus if I keep on playing a fool.. Sad isn't it..?