Question

cum se face: (√7 +2) la puterea minus unu?

Answer 1

(radical din 7 +2)^ -1 = 1/5

Answer 2

$a^{-1}= \frac{1}{a, }$, deci$( \sqrt{7}+2)^{-1}= \frac{1}{( \sqrt{7}+2)}= \frac{( \sqrt{7}-2)}{( \sqrt{7}+2)( \sqrt{7}-2)}= \frac{ \sqrt{7}-2}{7-4}= \frac{ \sqrt{7}-2}{3}$