Answer:
(4 x + 9) (16 x^2 - 36 x + 81)
Explanation:
Factor the following:
64 x^3 + 729
64 x^3 + 729 = (4 x)^3 + 9^3:
(4 x)^3 + 9^3
Factor the sum of two cubes. (4 x)^3 + 9^3 = (4 x + 9) ((4 x)^2 - (4 x) 9 + 9^2):
(4 x + 9) ((4 x)^2 - 4 9 x + 9^2)
4×9 = 36:
(4 x + 9) ((4 x)^2 - 36 x + 9^2)
Multiply each exponent in 4 x by 2:
(4 x + 9) (4^2 x^2 - 36 x + 9^2)
4^2 = 16:
(4 x + 9) (16 x^2 - 36 x + 9^2)
9^2 = 81:
Answer: (4 x + 9) (16 x^2 - 36 x + 81)