Question

O resultado de (√5-√2)(√2+√5) é ?

Answer 1

$(\sqrt{5}-\sqrt{2})(\sqrt{2}+\sqrt{5})$

Multiplique cada termo de um conjunto pelo termo do outro conjunto:
$(\sqrt{5}\times\sqrt{2})+(\sqrt{5}\times\sqrt{5})-(\sqrt{2}\times\sqrt{2})-(\sqrt{2}\times\sqrt{5})\\\\ =(\sqrt{5\times2})+(\sqrt{5 \times 5})-(\sqrt{2 \times 2})-(\sqrt{2\times5})\\\\ =\sqrt{10}+\sqrt{5^{2}}-\sqrt{2^{2}}-\sqrt{10}\\\\ =(\not\sqrt{\not10}-\not\sqrt{\not10})+(\not\sqrt{5^{\not2}}-\not\sqrt{2^{\not2}})\\\\ =5-2\\\\ \boxed{=3}$

Bons estudos!