分式基本性质的应用非常广泛,现归纳总结如下,供同学们学习时参考.一、用于分式的符号法则由-ab=-ab=-ba及--ba=--a b=--b a=ba可知分式的分子、分母与分式本身的符号,只要改变其中两个,分式的值不变.例1.下列各式中与分式-11-x的值相等的是()A.1-1-x B.-x-11C.1x-1D.1+1x解:∵ The application of the basic nature of the fractional formula is very extensive, and it is summarized as follows, for reference when students learn. First, the symbolic formula for fractions consists of -ab=-ab=-ba and -ba=--ab=-- Ba = ba is the sign of the numerator, denominator, and fraction itself of the fraction, as long as two of them are changed, the value of the fraction remains the same. Example 1. The values ​​in the following formulae that are equivalent to fractions -11-x are ( ) A.1-1-x B.-x-11C.1x-1D.1+1x ​​solution: ∵