Question

знайти значення виразу
(3-√2)×(5+√2)-(√2-1)²=

Answer 1

$(3-\sqrt{2})(5+\sqrt{2})-(\sqrt{2}-1)^2=$

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

$=13-2\sqrt{2}-3+2\sqrt{2}=10$