Question

Dau coroană!!!!!!!!
Imi trebuie chiar acum!!

Answer 1

$x ^{ - 1} = \frac{1}{5 \sqrt{7} } \\ rationalizam \: amplificand \: raportul \: cu \: \sqrt{7} \\ x ^{ - 1} = \frac{ \sqrt{7} }{35}$

Answer 2

$x = 5\sqrt{7} \\x^{-1} = 1/x = \frac{1}{5\sqrt{7}} =\frac{5\sqrt{7}}{25*7}= \frac{\sqrt{7} }{35} \\\\y =2\sqrt{7} \\y^{-1} = 1/y = \frac{1}{2\sqrt{7}} =\frac{2\sqrt{7}}{4*7}= \frac{\sqrt{7} }{14}$