This formula only applies to equations. The formula is to add or subtract a number on the left and right sides of the equation at the same time, so that the formula on the left side of the equation becomes a completely flat expansion, and then the equation can be factorized and solved. That is, the matching method is based on the complete square formula: (a+ or -b) square =a square+or -2ab square.

For example, if the formula you are talking about is not an equation, it cannot be solved by matching method. Let me give you an example:

2a？ -4a+2=0

Answer? -2a+ 1=0 (the quadratic coefficient should be changed to 1 first, so it is convenient to solve the problem by collocation method, so the quadratic coefficient 2 is divided by both sides of the equation).

(a- 1)？ =0 (the formula in the previous step found that the left side is completely flat, so according to the complete square formula, a? -2a+ 1 factorization is (a- 1)? Thereby completing the formula)

A- 1=0 (both sides of the final equation are squared at the same time)

A= 1 (result obtained)

Extended data:

In basic algebra, collocation method is a method for transforming quadratic polynomial into the sum of the square of linear polynomial and constant. This method converts the polynomial in the following form into coefficients A, B, C, D and E in the above expression, which can also be expressions and contain variables other than X. ..

Matching method is usually used to derive the root formula of quadratic equation: our aim is to turn the left side of the equation into a complete square. Since the complete square in the problem has the form of (x+y)2 = x2+2xy+y2, 2xy = (b/a)x can be deduced, so y = b/2a. Add y2 = (b/2a)2 to both sides of the equation, and you can get:

This expression is called the root formula of quadratic equation.

Reference: Baidu Encyclopedia-Matching Method