This textbook has no answers to after-class questions. When studying in senior grades, we usually refer to the supporting tutorial book "Advanced Algebra —— Guidance Series on Learning Methods of College Mathematics" edited by Yao Musheng, which is also published by Fudan Press. Most of the after-school questions will appear in this book, and some questions are more difficult than the after-school questions. I suggest you read this book directly, which is very helpful.