To solve this inequality, we can start by multiplying both sides by (1-х) to clear the denominator:

(1/5)^(2х+1) > 125(1-х)

Next, we can rewrite 125 as 5^3 because 5^3 = 125:

(1/5)^(2х+1) > 5^3(1-х)

Now, we can simplify the right side:

(1/5)^(2х+1) > 5^(3)(1-х)
(1/5)^(2х+1) > 5^(3) - 5^(4)х
(1/5)^(2х+1) > 125 - 625х

Now, we can rewrite the left side using the property that (a^b)^c = a^(b*c):

5^(-2х-1) > 125 - 625х

Now, we have a simpler form of the inequality. We can then rearrange it to isolate the terms with x on one side:

1/5^(2х+1) > 125 - 625х
5^(2х+1) < 1/(125 - 625х)
5^(2х+1) < 1/(125(1 - 5х))

At this point, we can see that it's a bit tricky because of the logarithms. To further simplify or solve for x, we may need to use logarithms or a numerical method. Let me know if you want to proceed in that direction.