\(2^{2005}=\left(2^5\right)^{401}=\overline{....2}\)

\(\overline{....2}:5\) dư 2

\(A=\dfrac{\sqrt{\left(x-5\right)^2}}{\left(4-x\right)^2}-\dfrac{x^2-25}{x-4}\)

Thay \(x=3\) thì

\(A=\dfrac{\sqrt{\left(3-5\right)^2}}{\left(4-3\right)^2}-\dfrac{3^2-25}{3-4}\)

\(A=\dfrac{\sqrt{\left(-2\right)^2}}{1^2}-\dfrac{9-25}{3-4}\)

\(A=\dfrac{\sqrt{4}}{1}-\dfrac{-16}{-1}\)

\(A=2-16=-14\)