Răspuns :

[tex]a)2\sqrt{x} 3*(\sqrt{3}-5\sqrt{6})-3\sqrt{2} (5\sqrt{2} -2)=\\6-10\sqrt{18} -30+6\sqrt{2}=\\6-30\sqrt{2}-30+6\sqrt{2} =\\=-24-24\sqrt{2}[/tex]

[tex]b)(\sqrt{8}+\sqrt3} )*(\sqrt{2}-\sqrt{27} )=\\(2\sqrt{2}+\sqrt{3} )*(\sqrt{2} -3\sqrt{3} )=\\4-6\sqrt{6}+\sqrt{6} -9=\\=-5-5\sqrt{6}[/tex]

[tex]c)(\frac{2}{\sqrt{5}})^{3}:(\frac{3}{2\sqrt{5}})^{2}=\\\frac{8}{5\sqrt{5}}:\frac{9}{4*5}=\\\frac{8}{5\sqrt{5}} *\frac{4*5}{9}=\\\frac{8}{\sqrt{5}} *\frac{4}{9} =\frac{32}{9\sqrt{5}}=\frac{32\sqrt{5} }{45}[/tex]

[tex]d)(5\sqrt{80} +3\sqrt{180} -\sqrt{320}):(-2\sqrt{10} )=\\(20\sqrt{5}+18\sqrt{5}-8\sqrt{5}):(2\sqrt{10})=\\30 \sqrt{5}:(-2\sqrt{10)}=-30\sqrt{5}:(-2\sqrt{10})=-\frac{30\sqrt{5}}{2\sqrt{10}}}=-\frac{15}{\sqrt{2}}=-\frac{15\sqrt{2} }{2} \\[/tex]

[tex]e)(\frac{1}{\sqrt{24}}-\frac{1}{\sqrt{54}}+\frac{1}{96})*\sqrt{6} =\\(\frac{1}{2\sqrt{6} } -\frac{1}{3\sqrt{6} } +\frac{1}{96})\sqrt{6}=\\(\frac{1}{6\sqrt{6}} +\frac{1}{96} )\sqrt{6}=\\(\frac{\sqrt{6} }{36} +\frac{1}{96})\sqrt{6}= \frac{1}{6} +\frac{\sqrt{6} }{96}[/tex]

[tex]f) (\frac{2+\sqrt{3} }{\sqrt{12} } +\frac{3+\sqrt{3} }{\sqrt{27} } -\frac{4+\sqrt{3} }{\sqrt{48} })*(\frac{1}{12\sqrt{3} })^{-1}=\\(\frac{2+\sqrt{5} }{2\sqrt{3} } +\frac{3+\sqrt{3} }{3\sqrt{3} } -\frac{4+\sqrt{3} }{4\sqrt{3} })*12\sqrt{3}=\\\frac{6(2+\sqrt{5})+4(3+\sqrt{3})-3(4+\sqrt{3}) }{12\sqrt{3}}*12\sqrt{3}=\\12+6\sqrt{5} +12+4\sqrt{3} -12-3\sqrt{3}=6\sqrt{5}+12+\sqrt{3}[/tex]