Question

упростите выражение(√5-2)²-(3+√5)²

Answer 1

$(\sqrt5-2)^2-(3+\sqrt5)^2=\\\\=(5-4\sqrt5+4)-(9+6\sqrt5+5)=9-4\sqrt5-14-6\sqrt5=\\\\=-5-10\sqrt5=-5\cdot (1+2\sqrt5)$