Question

(√5+2)²-4√5=9 rezolvare completa

Answer 1

$(\sqrt{5}+2)^2-4\sqrt{5} =$

$=(\sqrt{5})^2+2\cdot \sqrt{5}\cdot 2+2^2-4\sqrt{5}$

$= 5+4\sqrt{5}+4-4\sqrt{5}$

$=5+4+4\sqrt{5}-4\sqrt{5}$

$=\mathbf{9}$