Упростите выражение \((\dfrac{1}{\sqrt{a}-\sqrt{a-b}}+\dfrac{1}{\sqrt{a}+\sqrt{a+b}}):(1+\sqrt{\dfrac{a+b}{a-b}}).\)
\(\dfrac{\sqrt{a-b}}{b}\)
\(\dfrac{\sqrt{a}}{\sqrt{a+b}}\)
\(\dfrac{\sqrt{b}}{\sqrt{a-b}}\)
\(\dfrac{a}{\sqrt{a+b}}\)