Method of extracting common factor-If every term of a polynomial has a common factor, you can extract this common factor, thus transforming the polynomial into the product of two factors. This method of decomposing factors is called extracting common factors.

Formula method-including square difference formula, complete square formula and complete cube formula.

Group decomposition method-factor decomposition method is used to decompose factors that cannot be directly decomposed by common factor method and formula decomposition method. This factorization method is called grouping decomposition.

Cross multiplication-the multiplication on the left side of the cross is equal to the quadratic term coefficient, the multiplication on the right side is equal to the constant term, and the cross multiplication and addition are equal to the linear term.

I hope it can help you solve the problem.