(√7 - 2)² - (√13 - 2)(√13 + 2) =
= 7 - 4√7 + 4 - (13 - 4) =
= 11 - 4√7 - 9 = 2 - 4√7 = 2(1 - 2√2)
Odpowiedź:
[tex](\sqrt{7}-2)^2-(\sqrt{13}-2)(\sqrt{13}+2)=(\sqrt{7})^2-2\cdot\sqrt{7}\cdot2+2^2-((\sqrt{13})^2-2^2)=\\\\=7-4\sqrt{7}+4-(13-4)=11-4\sqrt{7}-9=2-4\sqrt{7}=2(1-2\sqrt{7})\\\\Odp.D[/tex]
