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分式是初中数学的重要内容之一,掌握分式的概念是学好分式有关知识的基础.初学分式概念时,应注意以下几点.一、忌轻易约分例1有理式x2x是分式还是整式?xπ呢?错解因为x2x=x,而x是整式,所以x2x是整式;xπ是分式.剖析分式概念是从形式上定义的,只要符合A B(A、B表示整式,且B中含有字母)的形式就是分式.判断一个式子是不是分式,不能看它化简后的结果,而应看它的本质.正解因为x2x的分子、分母均为整式,且分母中含有字母,所以x2x是分式.而xπ虽然是A B的形式,但分母π是常数,所以xπ是整式.
Fractional is one of the important content of junior high school mathematics, grasping the concept of fractional is the basis for learning the fractional knowledge .First, the concept of fractional, should pay attention to the following points. X2 is an integral; xπ is a fractional. Analytical fractional concept is formally defined, as long as AB (A, B for the whole, And B contains letters) is the form of fraction. Judgment of an equation is not a fraction, can not see it simplified results, but should look at its nature. Positive solution because x2x molecules, denominators are integral, and the denominator Contains letters, so x2x is a fraction, while xπ is AB, but denominator π is constant, so xπ is an integer.