After grouping, the common factor grouping decomposition method can be directly proposed. What is factorization? 2. Think back to the method of decomposing factors we have learned? Provide factorization, formula-square difference formula and complete square formula to transform a polynomial into the product of several algebraic expressions. The deformation of this formula is called factorization of this polynomial, which is also called factorization of this polynomial. Algebraic expression multiplication (a+b) (m+n) = a (m+n)+b (m+n) = am+an+BM+bnam+an+BM+bn = a (m+n)+b (m+n) = (a+b) (m+.