Răspuns:
[tex]x=(\frac{6\sqrt{7}+3 }{2\sqrt{7} } -\frac{7+9\sqrt{7} }{3\sqrt{7} }):\frac{5}{\sqrt{21} }=(\frac{3(6\sqrt{7}+3) }{6\sqrt{7} } -\frac{2(7+9\sqrt{7} )}{6\sqrt{7} }):\frac{5}{\sqrt{21} }=(\frac{18\sqrt{7}+9 }{6\sqrt{7} } -\frac{14+18\sqrt{7} }{6\sqrt{7} }):\frac{5}{\sqrt{21} }= \frac{18\sqrt{7}+9-14-18\sqrt{7} }{6\sqrt{7} } *\frac{\sqrt{21} }{5} =\frac{-5}{6\sqrt{7} }*\frac{\sqrt{7}*\sqrt{3}}{5}=-\frac{\sqrt{3} }{6} \\Deci~|x|=|-\frac{\sqrt{3} }{6}|=\frac{\sqrt{3} }{6}[/tex]
Explicație pas cu pas:
