The LCM of f(x) = 20(x - 1)^3 (x + 2)^2, g(x) = 250(x - 1)^2 (x + 2) is _______... i'm not sure how to do this at all...

It is rather unusal to ask for the least common multiple of functions. It is not clear how "least" is defined

In this case I'd guess the LCM is
500(x-1)^3 *(x+2)^2
If you divide that by either of your two functions, you get a product of monomials and integers, with a lowest integer coefficient.

500(x-1)^3 *(x+2)^2/f(x) = 25
500(x-1)^3 *(x+2)^2/g(x) = 2(x-1)(x+2)