In polynomial, special products can be obtained easily and mentally as it gives certain pattern to perform the operation.
Square of binomial (x+y)2 = x2 + 2xy +y2 (x-y)2 = x2 - 2xy +y2 In words; square the first term + the twice the product of the first and second term + the square of the second term
(x+y)(x-y) = X2- y2
(x+y+z)2= x2+y2+z2+ 2xy +2yz+2xz
(x+y)3 = x3 +3x2y +3xy2 + 3y3
(x-y)3 = x3 -3x2y +3xy2 - 3y3