Question

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\(\left(4+\sqrt{15}\right)\left(\sqrt{10}-\sqrt{6}\right)\left(\sqrt{4-\sqrt{15}}\right)\)

Answer 1

\(\left(4+\sqrt{15}\right)\left(\sqrt{10}-\sqrt{6}\right)\left(\sqrt{4-\sqrt{15}}\right)\)

\(=\left(\sqrt{4+\sqrt{15}}.\sqrt{4-\sqrt{15}}\right).\sqrt{2}.\left(\sqrt{5}-\sqrt{3}\right).\sqrt{4+\sqrt{15}}\)

\(=\sqrt{4^2-15}.\left(\sqrt{5}-\sqrt{3}\right).\sqrt{8+2\sqrt{15}}=\left(\sqrt{5}-\sqrt{3}\right)\left(\sqrt{\left(\sqrt{3}+\sqrt{5}\right)^2}\right)\)

\(=\left(\sqrt{5}-\sqrt{3}\right)\left(\sqrt{5}+\sqrt{3}\right)=5-3=2\)

Answer 2

kq cua mk la 2

Answer 3

giai thi dai dong lam