利用换元法解题时,如果待解题目中含有两个以上变元式时,常设一个变元式为新元,通过求解,使其它变元式也用这个新元素表示,从而达到换元解题的目的,在解题时要注意树立这种意识,掌握这个技巧,才能提高换元法解题水平.现举例说明.例1已知af(2x-3)+bf(3-2x)=2x, When using the substitution method to solve a problem, if the problem to be solved contains more than two variables, a permanent variable is a new element. Through solving, other variables are also represented by this new element, so that the change can be achieved. The purpose of the meta-solving problem is to pay attention to establishing this awareness and to master this skill in order to increase the problem-solving level of the yuan-changing method. Here is an example. Example 1 is known as af(2x-3)+bf(3-2x) )=2x,