[tex] |x|=4 \sqrt{15}
\\ b) \\ \lbrack {2 \sqrt{3} \rbrack=? \Longleftrightarrow \lbrack { \sqrt{8}\rbrack=? \Rightarrow \sqrt{4}\ \textless \ \sqrt{8}\ \textless \ \sqrt{9} \Rightarrow 2 \ \textless \ \sqrt{8}\ \textless \ 3 \Rightarrow \lbrack{2\sqrt{3}\rbrack=2[/tex]
[tex]c) \\ x*y=-4\sqrt{15}*2\sqrt{3}=-8\sqrt{45}[/tex]
[tex]d) \\ x:y= -4\sqrt{15}:2\sqrt{3}=-2\sqrt{5} = -\sqrt{20}[/tex]
[tex]e) \\ y^3=(-4\sqrt{15})^3=(-4\sqrt{15})^2*-4\sqrt15=16*15*-4\sqrt{15}=-960\sqrt15[/tex]
[tex]f) \\ a^{-n}=\frac{1}{a^{n}} \\ x^{-2}=(2\sqrt{3})^{-2}= \frac{1}{(2\sqrt{3})^2}=\frac{1}{4*3}=\frac{1}{12}, [/tex]
SPER CA TE-AM AJUTAT. SI CA O SA FIE BUN CEEA CE AM FACUT, BAFTA
