(A and B)? =a？ 2ab+b？

Characteristics of the formula: the left side is the sum of two numbers multiplied by the difference of two numbers, that is, the left side is the product of two binomials, in which one item (a) is exactly the same and the other items (b and -b) are opposite; On the right is the square difference between these two numbers, that is, the square of the same term MINUS the square of the opposite term of the right sign.

Matters needing attention

On the left side of the formula is the product of two terms, one of which is exactly the same.

The result on the right is the square difference of two terms in the multiplication formula, the square of the same term MINUS the square of the inverse term.

In the formula, a and b can be specific numbers, monomials or polynomials.