同学们,你们见过川剧中的“变脸”表演吗?演员在极短的时间内就将一张脸谱变为另一张脸谱.在进行多项式的因式分解时,有些多项式往往不能直接分解,需要对多项式进行适当的变形,创造条件完成分解.下面,就给同学们介绍几种常见的多项式的“变脸”技巧.一、变符号例1把多项式3n(2m-n)~2+(n-2m)~3因式分解.分析:由于(n-2m)~3=-(2m-n)~3,则多项式3n(2m-n)~2+(n-2m)~3的公因式是(2m-n)~2. Classmates, did you see the “face-up” show in Sichuan opera? In a very short period of time, the actor changed one Facebook page to another. In polynomial factorization, some polynomials often can not be directly Decomposition, the polynomial deformation of the appropriate need to create the conditions to complete the decomposition below, to give students a few common polynomials introduced “change face.” First, change the symbol Example 1 Polynomial 3n (2m-n) ~ (2m-n) ~ 2 + (n-2m) ~ 3 because of (n-2m) ~ 3 = - (2m-n) The common factor of 3 is (2m-n) ~ 2.