Remember, ask if you don't understand. Whether you understand or not in class, take notes first and then ask the teacher slowly after class. In addition, do some exercises that suit you (don't do it deliberately if you don't know how to do that part), and you should understand all the examples in the book. The following two are more important about a linear function, and the most important is the image: 1). As long as you see the problem of the function, you can draw the image immediately, no matter how simple it is (you can draw a straight line with two sets of data). 2) If you can find the analytical formula, try to find the analytical formula first, and then draw the image. Practice this part more in winter vacation. 3) Understand the basic features of function images, such as straight lines; Make an accurate judgment, such as which quadrants it has passed, which is very helpful for judging the range and positive and negative. Function is the most demanding part of junior high school mathematics. There will be two functions in junior high school, so the foundation is very important. As for factorization, this is a problem derived from the equation. Junior high school is not demanding. Every time I try to turn it into a formula-related form, that is, the square of (A+B) and cross multiplication (ask the teacher if you don't understand), which is one of the most effective ways to solve factorization. This formula can be used in junior high school entrance examination. ! ! ! ! ! ! ! ! In addition, congruent triangles is a unit that must be mastered in the second grade. The third grade will be tested together with similar trigonometric functions and quadratic functions, with 29 points in the senior high school entrance examination!