Răspuns:
- [tex] \frac{3 \sqrt{2} }{2} [/tex]
- [tex] \frac{5 \sqrt{3} }{3} [/tex]
- √5/4
- [tex]81[/tex]
Explicație pas cu pas:
[tex]a) \: \frac{1}{ \sqrt{2} } + \frac{2}{ \sqrt{8} } + \frac{3}{ \sqrt{18} } = [/tex]
[tex] \frac{ \sqrt{2} }{2} + \frac{2}{ 2\sqrt{2} } + \frac{3}{3 \sqrt{2} } = [/tex]
[tex] \frac{ \sqrt{2} }{2} + \frac{1}{ \sqrt{2} } + \frac{1}{ \sqrt{2} } = [/tex]
[tex] \frac{ \sqrt{2} }{2} + \frac{ \sqrt{2} }{2} + \frac{ \sqrt{2} }{2} = [/tex]
[tex] \frac{ \sqrt{2} + \sqrt{2} + \sqrt{2} }{2} = [/tex]
[tex] \frac{3 \sqrt{2} }{2} [/tex]
[tex]b) \: \frac{6}{ \sqrt{3} } - \frac{8}{ \sqrt{12} } + \frac{9}{ \sqrt{27} } = [/tex]
[tex]2 \sqrt{3} - \frac{8}{2 \sqrt{3} } + \frac{9}{3 \sqrt{3} } = [/tex]
[tex]2 \sqrt{3} - \frac{4}{ \sqrt{3} } + \frac{3}{ \sqrt{3} } = [/tex]
[tex]2 \sqrt{3} - \frac{4 \sqrt{3} }{3} + \sqrt{3} = [/tex]
[tex] \frac{5 \sqrt{3} }{3} [/tex]
[tex]c) \: ( \frac{1}{ \sqrt{5} } - \frac{1}{ \sqrt{20} } + \frac{1}{ \sqrt{45} } - \frac{1}{ \sqrt{125} } ) \times (2 - \frac{1}{38} ) = [/tex]
[tex]( \frac{1}{ \sqrt{5} } - \frac{1}{2 \sqrt{5} } + \frac{1}{3 \sqrt{5} } - \frac{1}{5 \sqrt{5} } ) \times \frac{75}{38} = [/tex]
[tex] \frac{19}{30 \sqrt{5} } \times \frac{75}{38} = [/tex]
[tex] \frac{1}{2 \sqrt{5} } \times \frac{5}{2} = [/tex]
[tex] \frac{5}{4 \sqrt{5} } = [/tex]
[tex] \frac{ \sqrt{5} }{4} [/tex]
[tex]d) \: ( \sqrt{54} - \frac{6}{ \sqrt{6} } ) \times ( \frac{48}{ \sqrt{6} } - \frac{15}{ \sqrt{24} }) = [/tex]
[tex](3 \sqrt{6} - \sqrt{6} ) \times ( \frac{48}{ \sqrt{6} } - \frac{15}{2 \sqrt{6} } ) = [/tex]
[tex]2 \sqrt{6} \times \frac{81}{2 \sqrt{6} } = [/tex]
[tex]81[/tex]