Answer:
4.(a + b)²
The (a + b)2 formula is used to find the square of a binomial. This formula is also used to factorize some special types of trinomials. This formula is one of the algebraic identities. The (a + b)2 formula is the formula for the square of the sum of two terms.
5.(a+b)-²
6.(a + b + c)2 = a2 + b2 + c2 + 2ab + 2bc + 2ca.
