分式的化简求值是分式学习中的一类常见题型,然而,在许多情况下,分式的求值并不是简单、机械地化简、代入、计算,而需要通过适当的技巧才能达到目的,整体思想则是其中一种常见的思维形式,为方便同学们的学习,现归纳几类,供参考。一巧妙变换条件,直接求值例1(2014年·十堰)已知a~2-3a+1=0,则a+1/a-2的值为(). However, in many cases, fractional evaluation is not simple, mechanical simplification, substitution, calculation, and the need to adopt appropriate skills In order to achieve the goal, the overall idea is one of the common forms of thinking, for the convenience of students learning, are summarized in several categories for reference. A clever transformation conditions, the direct evaluation of Example 1 (2014 · Shiyan) a ~ 2-3a +1 = 0, then the value of a + 1 / a-2 ().