在数学中考题以及各类竞赛中,常会出现已知某分式方程的解的情况,比如有无解、有无增根、解的正负等,来求另一个字母的取值范围,此类题目考查学生思维的全面性和逆向思维能力,同学们由于对分式方程解的情况分析不透彻,常会有错解、多解或漏解的情况发生,下面列举几例加以说明. In mathematics exams and various competitions, it often happens that some solutions of some fractional equations are known, such as the existence of solutions, the existence of roots, the solution of positive and negative, etc., to find the value of another letter, this Class topics examining students’ comprehensive thinking and ability to reverse thinking, students due to the incomplete analysis of the solution to the partial equation, often misunderstood, multiple solutions or missed cases, the following list a few examples to illustrate.