判断正反比例一般可以分如下三个步骤:一找。找出两种量是不是相关联的量。如果一种量变化,另一种量也随着变化,这两种量是相关联的量。二写。写出相关联的两种量有什么关系。(1)这两种量能不能写成除法关系式?如果能写成除法关系式,再看商(比值)是否一定;(2)这两种量能不能写成乘法关系式,如果能写成乘法关系式,再看两种量相乘的积是不是一定。 To determine the positive and negative proportion can generally be divided into the following three steps: one to find. Find out whether the two quantities are related quantities. If one kind of quantity changes, the other kind also changes with the amount, these two kinds of quantity are correlated quantity. Second write. What is the relationship between the two quantities associated? (1) The two quantities can not be written into the division relationship? If you can write the division relationship, see the business (ratio) is certain; (2) The two quantities can not be written as a multiplication relationship, Look at the multiplication of the two products is not necessarily the product.