When we study we often do it in one sitting and this is not the best way to learn. I suggest that you start with easier homework and work on it for 20-30 minuets. Then, take a break, get something to eat, or do something that doesn't require much thinking. After, this break you choose another subject to do your homework. Repeat what you did the first time and before you know it the work will be done. It isn't "boredom " that is your problem, but organization.