Question

Dau coroana si 50 puncte!​

Answer 1

$x=(\frac{8}{\sqrt{18}} +\frac{6}{\sqrt{2}}) \frac{\sqrt{2}}{13} =\frac{8+18}{3\sqrt{2}} \frac{\sqrt{2}}{13} =\frac{2\sqrt{2}}{3\sqrt{2}} =\frac{2}{3}$

$y=(\frac{1}{\sqrt{3}} -\frac{5}{7\sqrt{3}})\frac{14}{\sqrt{3}} =\frac{2}{7\sqrt{3}} \frac{14}{\sqrt{3}} =\frac{4}{3}$

$x+y=\frac{2}{3} +\frac{4}{3} =2$  ∈ $N$