$\begin{array}{l}A = \dfrac{x^2 + 2x - y^2 - 2y}{x^2 - y^2}\\ ĐKXĐ:\,x^2 -y^2 \ne 0\Leftrightarrow x \ne \pm y\\ A = \dfrac{(x^2 - y^2) + (2x - 2y)}{x^2 - y^2}\\ \to A = 1 + \dfrac{2(x-y)}{(x-y)(x+y)}\\ \to A = 1 + \dfrac{2}{x+y}\\ Với\,\,x=5;\,y = 6\,\,ta\,\,được:\\ A = 1 + \dfrac{2}{5+6} = 1 + \dfrac{2}{11} = \dfrac{13}{11}\end{array}$