在分式加减运算中,若能根据分式的结构特点,使用通分的技巧,不仅可以保证运算的正确性,而且可以提高解题的速度,收到事半功倍之效。一、整体通分例1计算x3x-1-x2-x-1。解:原式=x3x-1-(x2+x+1)=x3x-1-(x-1)(x2+x+1)x-1=x3x-1-x3-1x-1=1x-1。二、拆项通分例2计算a-bab+b-cbc+c-ac In the addition and subtraction of fractions, if we can use the technique of pass points according to the structural characteristics of fractions, we can not only ensure the correctness of the calculations, but also increase the speed of problem solving and receive more effective results. First, the overall pass case 1 calculates x3x-1-x2-x-1. Solution: The original formula = x3x-1-(x2+x+1)=x3x-1-(x-1)(x2+x+1)x-1=x3x-1-x3-1x-1=1x-1 . Second, the decommissioning pass Case 2 calculation a-bab+b-cbc+c-ac