分式的概念和运算是初中数学中重要的基础知识,在中考中常占有一定的分量,因此必须加以重视,理解分式概念时应注意以下四点:一、不可轻易约分确定分式有、无意义时,切忌先约分后求解.例1若分式万竺典不无意义,则 Fractional concepts and operations are important basic knowledge in junior high school mathematics, and often occupy a certain amount of weight in the mid-term exam. Therefore, we must pay attention to it. When understanding the fractional concept, we should pay attention to the following four points: First, it is not easy to determine whether fractions have, When there is no meaning, avoid subtraction first. Example 1 If the formula is not meaningless, then