1. 27x3+64y3 2. 125a3-1 3. 1+729x3 4. 1000-8b3

(1) (3 x + 4 y) (9 x^{2} - 12 x y + 16 y^{2})(2) (5 a -1) (25 a^{2} + 5 a + 1)(3) 729 x^{3} + 1(4) 8 (5 - b) (25 + 5 b + b^{2})