If you're having trouble with homework, I think it would be helpful to ask your friends or even your teacher. I know I had quite a few questions every lesson. Sometimes my problems end up being silly mistakes, other times they were genuinely difficult questions. In this case, just asking your teacher during maths lessons, when other people's working on classwork, can really alleviate the struggles of figuring out harder questions at home. HSC's all about managing time properly, and spending 40min on a homework question is not efficient, especially when it could be solved by an explanation by a friend/teacher in 5min. It's also essential that you don't end up skipping a lot of questions you don't know how to do, as this can be detrimental later on ): But instead ask for help from people around you, whether they be your friend, tutor or teacher. Good luck with your studies ^^