Giải thích các bước giải:
$\dfrac{x^2y^2}{xy}:(x-y)^2+\dfrac{(x+y)^2}{x^2-y^2}$
$=xy:(x-y)^2+\dfrac{(x+y)^2}{(x+y)(x-y)}$
$=\dfrac{xy}{(x-y)^2}+\dfrac{x+y}{x-y}$
$=\dfrac{xy}{(x-y)^2}+\dfrac{(x+y)(x-y)}{(x-y)^2}$
$=\dfrac{xy+(x+y)(x-y)}{(x-y)^2}$
$=\dfrac{xy+x^2-y^2}{(x-y)^2}$