Answer
(5 - 4a + b)(16$a^{2}$ + $b^{2}$- 8ab + 20a - 5b + 25)
Work Step by Step
125 - $(4a - b)^{3}$ is a difference of cubes, so we write it as a difference of cubes and factor:
$5^{3}$ - $(4a - b)^{3}$
= (5 - (4a - b))($5^{2}$ + 5(4a - b) + $(4a - b)^{2}$)
= (5 - 4a + b)(25 + 20a - 5b + 16$a^{2}$ - 8ab + $b^{2}$)
= (5 - 4a + b)(16$a^{2}$ + $b^{2}$- 8ab + 20a - 5b + 25)
