因式分解作为重要的恒等变形之一,是解决数学问题的有力工具,因此学好因式分解,很有必要.要学好因式分解,必须注意以下“六忌”.一、忌概念不清例1把x2-4+3x分解因式.错解原式=(x+2)(x-2)+3x.分析分解因式是把一个多项式化成几个整式积的形式,本题解法与因式分解的定义不符.这样的变形,不是分解因式.正解原式=x2+3x-4=(x-1)(x+4). Factorization as an important one of the equal deformation is a powerful tool to solve mathematical problems, so learn good factorization, it is necessary to learn good factorization, we must pay attention to the following “six bogey.” First, avoid the concept Not clear Example 1 x2-4 +3 x factorization. The original solution = (x +2) (x-2) +3 x. Factorization analysis is to decompose a polynomial into several integral product form, the solution Does not correspond to the definition of factorization. Such a transformation is not a factorization. Positive solution Original = x2 + 3x-4 = (x-1) (x + 4).