125x^3 - 8
This is the difference of cubes
The factorization of a^3 - b^3 = ( a - b) (a^2 + ab + b^2)
"a" is the cube root of the first term = 5x
"b" is the cube root of the second term = 2
So we have
( 5x - 2) ( [ 5x ]^2 + [ 5x * 2 ] + 2^2 ] =
(5x - 2) (25x^2 + 10x + 4 )