0\; ,\; b>0" alt="(\frac{a}{\sqrt{ab}-b}-\frac{\sqrt{b}}{\sqrt{b}-\sqrt{a}})\cdot \frac{(\sqrt{a}-\sqrt{b})\cdot b}{a+b}=(\frac{a}{\sqrt{b}\cdot (\sqrt{a}-\sqrt{b})}+\frac{\sqrt{b}}{\sqrt{a}-\sqrt{b}})\cdot \frac{(\sqrt{a}-\sqrt{b})\cdot b}{a+b}=\\\\=\frac{a+\sqrt{b}\cdot \sqrt{b}}{\sqrt{b}\cdot (\sqrt{a}-\sqrt{b})}\cdot \frac{(\sqrt{a}-\sqrt{b})\cdot b}{a+b}=\frac{a+b}{\sqrt{b}\cdot (\sqrt{a}-\sqrt{b})}\cdot \frac{(\sqrt{a}-\sqrt{b})\cdot b}{a+b}=\sqrt{b}\; ,\; \; a>0\; ,\; b>0" align="absmiddle" class="latex-formula">