Question

(3-sqrt2)(5+sqrt2) - (sqrt2 - 1)^2 (полное решение)

Answer 1

$\tt(3-\sqrt{2})(5+\sqrt{2})-(\sqrt{2}-1)^2=\\\\=15+3\sqrt{2}-5\sqrt{2}-2-(2-2\sqrt{2}+1)=\\\\=13-2\sqrt{2}-2+2\sqrt{2}-1=10$