对于某些分式型竞赛问题,用常规方法求解困难时,若根据分式的结构特征和内在规律采用取倒数的方法来求解,往往具有简洁明快的特点.现举例说明,供同学们学习参考. For some fractional competition problems, when the conventional method is used to solve the difficulty, if the solution is based on the structure characteristics and internal rules of the fractions, the inverse method is often used to solve the problems. This is a simple and clear feature. Here is an example for the students to learn .