Answers

You should compare your answer with the suggested answer. This extra bit of mental effort is an important part of active learning, and an important part of studying. Sometimes the questions are drill type questions and your answer should exactly match the answer given here. Other times the questions are open ended, and your answer is expected to be different. But if you don't answer at all, you are not spending your time as wisely as you could.

This is also good training for how to read any text book. As you read a text, think up your own questions, or look ahead to the exercises, or guess what comes next. Keeping your mind engaged with questions is an effective way to learn.