(25^-0.4 x 5^0.2 x 5^0.8)^2

First, let's simplify the expression inside the parentheses:
25^-0.4 = 1/25^0.4 = 1/5^0.8
5^0.2 x 5^0.8 = 5^(0.2 + 0.8) = 5^1 = 5

Now substitute back into the original expression:
(1/5^0.8 x 5)^2
= (1/5 x 5)^2
= 1^2
= 1

Therefore, (25^-0.4 x 5^0.2 x 5^0.8)^2 = 1.