Răspuns :
1)
([tex] \frac{2}{ \sqrt{2} } [/tex]-[tex] \frac{3}{ \sqrt{3} }[/tex])⇒[tex]( \frac{2}{ \sqrt{2} } - \frac{3}{ \sqrt{3} })( \sqrt{6} - \frac{ \sqrt{3} }{18}- \frac{10}{ \sqrt{75}})( \sqrt{6})= \sqrt{6}( \frac{2}{ \sqrt{2}}- \frac{3}{ \sqrt{3} } - \frac{3}{ \sqrt{18}}- \frac{10}{ \sqrt{10}})= [/tex][tex]=( \frac{2}{ \sqrt{2} }- \frac{3}{ \sqrt{3} } - \frac{3}{3 \sqrt{3} } + \frac{10}{5 \sqrt{3}} )= \sqrt{6}( \frac{1}{ \sqrt{2} } - \frac{1}{ \sqrt{3} })= \frac{ \sqrt{6} }{ \sqrt{2} } - \frac{ \sqrt{6} }{ \sqrt{3} }= \sqrt{3} - \sqrt{2} [/tex]
2) a=|2[tex] \sqrt{7} [/tex]-8|
2[tex] \sqrt{7} [/tex]=[tex] \sqrt{28} [/tex]
[tex] \sqrt{28} \geq \sqrt{64} [/tex]⇒a=[tex]2 \sqrt{7}+8 [/tex]
b=[tex]2 \sqrt{7}+8 [/tex]
Mg=[tex]\sqrt{(8-2 \sqrt{7})(8+2 \sqrt{7})}= \sqrt{8 ^{2} -(2 \sqrt{7)^{2}}}= \sqrt{16-14}= \sqrt{2} [/tex]
([tex] \frac{2}{ \sqrt{2} } [/tex]-[tex] \frac{3}{ \sqrt{3} }[/tex])⇒[tex]( \frac{2}{ \sqrt{2} } - \frac{3}{ \sqrt{3} })( \sqrt{6} - \frac{ \sqrt{3} }{18}- \frac{10}{ \sqrt{75}})( \sqrt{6})= \sqrt{6}( \frac{2}{ \sqrt{2}}- \frac{3}{ \sqrt{3} } - \frac{3}{ \sqrt{18}}- \frac{10}{ \sqrt{10}})= [/tex][tex]=( \frac{2}{ \sqrt{2} }- \frac{3}{ \sqrt{3} } - \frac{3}{3 \sqrt{3} } + \frac{10}{5 \sqrt{3}} )= \sqrt{6}( \frac{1}{ \sqrt{2} } - \frac{1}{ \sqrt{3} })= \frac{ \sqrt{6} }{ \sqrt{2} } - \frac{ \sqrt{6} }{ \sqrt{3} }= \sqrt{3} - \sqrt{2} [/tex]
2) a=|2[tex] \sqrt{7} [/tex]-8|
2[tex] \sqrt{7} [/tex]=[tex] \sqrt{28} [/tex]
[tex] \sqrt{28} \geq \sqrt{64} [/tex]⇒a=[tex]2 \sqrt{7}+8 [/tex]
b=[tex]2 \sqrt{7}+8 [/tex]
Mg=[tex]\sqrt{(8-2 \sqrt{7})(8+2 \sqrt{7})}= \sqrt{8 ^{2} -(2 \sqrt{7)^{2}}}= \sqrt{16-14}= \sqrt{2} [/tex]