Answer:
4x-5
Step-by-step explanation:
The area of a square is
A = s^2
16x^2 - 40x+25 = s^2
Take the square root of each side
sqrt(16x^2 - 40x+25) =sqrt( s^2)
Recognizing that the left hand side is a perfect square trinomial
sqrt((4x-5)^2) = s
4x-5 =s
The side length is 4x-5
