Question

Найдите значение выражения (5+√2)²+(5-√2)²

Answer 1

$\displaystyle\bf\\\Big(5+\sqrt{2} \Big)^{2} +\Big(5-\sqrt{2} \Big)^{2} =5^{2} +2\cdot 5\cdot \sqrt{2} +(\sqrt{2} )^{2} +5^{2} -2\cdot 5\cdot \sqrt{2} +(\sqrt{2} )^{2} =\\\\\\=25+10\sqrt{2} +2+25-10\sqrt{2} +2=54\\\\\\Otvet: \ 54$