1. Understand method of substitution's concept: method of substitution replaced a variable in a complex expression or equation with another variable, thus simplifying the problem-solving process.
2. Learn the common substitution forms: the common substitution forms are algebraic substitution and trigonometric function substitution. Algebraic substitution is to replace the variables in one algebra with another algebra, and trigonometric substitution is to replace the independent variables in a trigonometric function with another variable.
3. Do more exercises: By doing a lot of exercises, you can be familiar with different types of substitution problems and master the problem-solving methods in different situations. You can choose some typical examples to analyze and answer, and understand the ideas and methods to solve the problem.
4. Pay attention to the equivalence of substitution: when doing substitution, pay attention to the equivalence of substitution, that is, the expression or equation after substitution has the same mathematical meaning as the original expression or equation. Only by maintaining equivalence can we solve the problem correctly by substitution.
5. Summary: In the process of study and practice, summarize and summarize the knowledge points and problem-solving methods learned in time, and form your own mind map or notes to facilitate review and review.
6. Ask for help: If you encounter difficulties or don't understand, you can ask teachers, classmates or parents for help and answer questions.
In a word, to master method of substitution in junior high school mathematics quickly, we need to understand concepts, learn common forms, do more exercises, pay attention to equivalence, summarize and ask for help. Through continuous study and practice, I believe I can master method of substitution and use it flexibly to solve practical problems.