解一次方程组的基本思想是消元,代入法和加减法是最基本的消元方法,务必熟练掌握.现选几例介绍如何根据方程组的结构和系数的特点,更合理、更迅速地消元的方法与技巧,供同学们参考. The basic idea of ​​solving a system of equations is elimination. Substitution and addition and subtraction are the most basic elimination methods and must be mastered. Several examples are presented to show how to use the characteristics of the equation group structure and coefficients to make it more reasonable and more rapid. Elimination of the method and skills for students to refer to.