1,2,6,7,8 решите во вложении

[latex]\displaystyle 2)..(9x^{-5} :x^{-1})^{-2}( \frac{x^{3} }{3})^{-3}= \frac{x^{8}}{3^{4} }*\frac{3^{3}}{x^{9} }= \frac{1}{3x} \\ \\3)..(- \frac{2a^{-3}}{b})^{-2}(a^{2}b)^{-3}= (- \frac{b}{2a^{3}})^{2}a^{-6}b^{-3}= \frac{1}{4}b^{2}a^{6}a^{-6}b^{-3}=\frac{1}{4b} \\ \\ 4)..(a^{-2}-b^{-2})(a+b)^{-1}+b^{-2}a^{-1}= \frac{b^{2}-a^{2}}{a^{2}b^{2}(b+a) } + \frac{a}{a^{2}b^{2} }= \\ \\ = \frac{b-a+a}{a^{2}b^{2} }= \frac{1}{a^{2}b }[/latex] [latex]6)..\displaystyle \\ \frac{y^{ \frac{1}{3} }z^{ \frac{1}{2} }-z }{y^{ \frac{2}{3} }-z}+ \frac{y}{y+y^{ \frac{2}{3} }z^{ \frac{1}{2} } }= \frac{(y^{ \frac{1}{3} }z^{ \frac{1}{2} }-z)(y+y^{ \frac{2}{3} }z^{ \frac{1}{2} })+y(y^{ \frac{2}{3} }-z)}{(y^{ \frac{2}{3} }-z)(y+y^{ \frac{2}{3} }z^{ \frac{1}{2} })}= \\ \\ = \frac{y^{ \frac{4}{3} }z^{ \frac{1}{2} }-zy+yz-y^{ \frac{2}{3} }z^{ \frac{3}{2} }+y^{ \frac{5}{3} }-yz}{y^{\frac{5}{3} }-zy+y^{\frac{4}{3} }z^{\frac{1}{2} }-y^{\frac{2}{3} }z^{\frac{3}{2}}}= \\ \\[/latex][latex] \displaystyle =\frac{y^{\frac{5}{3} }-zy+y^{\frac{4}{3} }z^{\frac{1}{2} }-y^{\frac{2}{3} }z^{\frac{3}{2}}}{y^{\frac{5}{3} }-zy+y^{\frac{4}{3} }z^{\frac{1}{2} }-y^{\frac{2}{3} }z^{\frac{3}{2}}} =1[/latex] [latex]\displaystyle 7)..( \frac{ \sqrt{a}}{ \sqrt{b} }+ \frac{\sqrt{b}}{\sqrt{a}}-2)* \frac{\sqrt{ab}}{\sqrt{a}-\sqrt{b}}=( \frac{a+b}{\sqrt{ab}}-2)* \frac{\sqrt{ab}}{\sqrt{a}-\sqrt{b}}= \\ \\ \frac{a+b}{{\sqrt{a}-\sqrt{b}}}- \frac{2 \sqrt{ab} }{ \sqrt{a}- \sqrt{b} }= \frac{a-2 \sqrt{a} \sqrt{b}+b}{ \sqrt{a}- \sqrt{b} }= \frac{( \sqrt{a}- \sqrt{b})^{2}}{ \sqrt{a}- \sqrt{b} }= \sqrt{a}- \sqrt{b} [/latex] [latex]\displaystyle 8)..(\sqrt{a}-\frac{\sqrt{ab}+b}{\sqrt{a}+\sqrt{b}})(\frac{\sqrt{a}}{\sqrt{a}+ \sqrt{b}}+\frac{\sqrt{b}}{\sqrt{a}-\sqrt{b}}+\frac{2\sqrt{ab}}{a-b})=\\\\=(\frac{\sqrt{a}(\sqrt{a}+\sqrt{b})-\sqrt{ab}+b}{\sqrt{a}+\sqrt{b} })(\frac{a-\sqrt{ab}+b+\sqrt{ab}}{(\sqrt{a}+\sqrt{b})(\sqrt{a}-\sqrt{b})}+\frac{2\sqrt{ab}}{a-b})=\\\\=(\frac{a+b+\sqrt{ab}-\sqrt{ab}}{\sqrt{a}+ \sqrt{b}})(\frac{a+2\sqrt{ab}+b}{a-b})=(\frac{a+b}{\sqrt{a}+\sqrt{b}})(\frac{\sqrt{a}+\sqrt{b} }{\sqrt{a}-\sqrt{b}})=\\ [/latex] [latex]\displaystyle = \frac{a+b}{ \sqrt{a}- \sqrt{b} } [/latex]