b) 27x^3 + 54x^2y + 36xy^2 + 8y^3;
b) 27x3 + 54x2y + 36xy2 + 8y3;
b) 27x3 + 54x2y + 36xy2 + 8y3
= (3x)3 + 3 . (3x)2 . 2y + 3 . 3x . (2y)2 + (2y)3
= (3x + 2y)3;