Question

Imi trebuie urgent dau coroana

Answer 1

${(2 - \sqrt{5}) }^{2} + (2 - \sqrt{5})(2 + \sqrt{5}) + (2 + \sqrt{5}) ^{2} = \\ \\ 4 - 4 \sqrt{5} + 5 - (2 - \sqrt{5}) \times (2 + \sqrt{5}) + 4 + 4 \sqrt{5} + 5 = \\ \\ 4 + 5 - (4 - 5) + 4 + 5 = \\ \\ 4 + 5 - ( - 1) + 4 + 5 = \\ \\ 4 + 5 + 1 + 4 + 5 = \\ \\ 19$