Avaldised

\left[\frac{x}{x^2-y^2}-\frac{x}{\left(x-y\right)^2}\right]\cdot\frac{y^2-2xy+x^2}{2x} = 

\left(\frac{b}{a^2+ab}-\frac{2b-a}{b^2+ab}\right)\ :\ \frac{\left(a-b\right)^2}{a^2b+ab^2} = 

\left(\frac{x-1}{x-9}\right)^{-1}\left(\frac{x+7}{x^2-18x+81}+\frac{x+5}{x^2-81}\right) = 

\frac{4}{x^2+2x-15}+\frac{2x}{x^2-25}+\frac{1}{x-5} = 

\frac{\sqrt{a}+1}{\sqrt{a}-1}-\frac{\sqrt{a}-1}{\sqrt{a}+1}+4\sqrt{a} = 

\left(\sqrt{a}-\frac{1}{\sqrt{a}}\right)\left(\sqrt{a}+\frac{1}{\sqrt{a}}\right) = 

\left(\frac{1}{\sqrt{x}-1}-\frac{2}{x-1}\right)\left(\sqrt{x}-1\right)^{-1} = 

\left(\frac{2x}{x-4}+\frac{x}{\sqrt{x}+2}\right):\frac{x\sqrt{x}}{\sqrt{x}-2} =