Digital circuits

So just when I was starting to understand everything, we have to go and start a new chapter. I was feeling really good about this class now that we have started chapter 4, I am right back to feeling over whelmed and to top it all off we will be having and exam in a couple weeks. Some of the stuff in the chapter is easy but when it comes down to simplifying I just get lost and can't figure it out. I just don't understand where they get some of the answers. I can do some of the smaller one by doing the different laws and combining like terms, but I just need to figure out a simpler way for me to understand it. Doing the hands on parts like the labs I feel very confident but when it comes to the book work I'm a little lost. If anyone has any suggestions please feel free.