Junior high school students' mathematics cohesion course. Junior high school mathematics cohesion course is written by experienced teachers, covering the basic knowledge of junior high school mathematics, including functions, equations, algebra, geometry and so on. This book is suitable for beginners and can help them better understand the basic concepts and skills of mathematics. Xi 'an, referred to as "Gao", was called Chang 'an and Haojing in ancient times. It is the capital of Shaanxi Province, a sub-provincial city, a megacity, the core city of Guanzhong Plain urban agglomeration, and an important central city in western China determined by the State Council.