Question

scrie inversul lui x
x=( -$\sqrt{14}$ + 2$\sqrt{10}$ ):$\sqrt{2}$ + (6$\sqrt{15$ -8$\sqrt{21}$ ) : (-2$\sqrt{3}$ )

Answer 1

Răspuns:

Explicație pas cu pas:

$=-\sqrt{7} +2\sqrt{5}-3\sqrt{5}+4\sqrt{7}=3\sqrt{7}-\sqrt{5}$

$\frac{1}{x} =\frac{1}{3\sqrt{7} -\sqrt{5} }=\frac{3\sqrt{7}+\sqrt{5}}{(3\sqrt{7}-\sqrt{5})(3\sqrt{7}+\sqrt{5})} =\frac{3\sqrt{7}+\sqrt{5}}{(3\sqrt{7})^{2}-(\sqrt{5})^{2} }=\frac{3\sqrt{7} +\sqrt{5}}{63-5}= \frac{3\sqrt{7} +\sqrt{5}}{58}$

Answer 2

x = $\it (-\sqrt{14} + 2\sqrt{10}) : \sqrt{2} + (6\sqrt{15} - 8\sqrt{21}) : (-2\sqrt{3} )$

x = $\it -\sqrt{7} + 2\sqrt{5} - 3\sqrt{5} + 4\sqrt{7}$

x = $\it 3\sqrt{7} - \sqrt{5}$

$\it ~^{3\sqrt{7} + \sqrt{5}) } \frac{1}{3\sqrt{7} - \sqrt{5}  } = \frac{3\sqrt{7} + \sqrt{5}  }{(3\sqrt{7})^{2} - (\sqrt{5})^{2} } = \frac{3\sqrt{7} + \sqrt{5} }{63 - 5} = \frac{3\sqrt{7} + \sqrt{5} }{58}$