Bài 1: rút gọn
I=\(\sqrt{4+\sqrt{10+2\sqrt{5}}}+\sqrt{4-\sqrt{10+2\sqrt{5}}}\)
K=\(\sqrt{94-42\sqrt{5}}-\sqrt{94+42\sqrt{5}}\)
Bài 2: tính
Y=\(2+\sqrt{17-4\sqrt{9+4\sqrt{5}}}\)
Z=\(\sqrt[3]{7+5\sqrt{2}}+\sqrt[3]{7-5\sqrt{2}}\)
T=\(\sqrt{3-\sqrt{5}}\left(3+\sqrt{5}\right)\left(\sqrt{10}-\sqrt{2}\right)\)
Câu 2:
a: \(=2+\sqrt{17-4\left(\sqrt{5}+2\right)}\)
\(=2+\sqrt{17-4\sqrt{5}-8}\)
\(=2+\sqrt{9-4\sqrt{5}}\)
\(=2+\sqrt{5}-2=\sqrt{5}\)
b: \(=\sqrt{2}+1+1-\sqrt{2}=2\)
c: \(=\sqrt{6-2\sqrt{5}}\cdot\left(3+\sqrt{5}\right)\left(\sqrt{5}-1\right)\)
\(=\left(6-2\sqrt{5}\right)\left(3+\sqrt{5}\right)\)
\(=18+6\sqrt{5}-6\sqrt{5}-10=8\)