h: \(\sqrt{5-6\sqrt{5}+9}\)
\(=\sqrt{5-2\cdot\sqrt{5}\cdot3+3^2}\)
\(=\sqrt{\left(3-\sqrt{5}\right)^2}=\left|3-\sqrt{5}\right|=3-\sqrt{5}\)
i: \(\sqrt{\left(3-\sqrt{10}\right)^2}+\sqrt{\left(\sqrt{10}-5\right)^2}\)
\(=\sqrt{10}-3+5-\sqrt{10}\)
=5-3
=2
k: \(x-\sqrt{x^2+8x+16}\)
\(=x-\sqrt{\left(x+4\right)^2}\)
\(=x-\left|x+4\right|\)
\(=x-\left(x+4\right)\)(Vì x>-4)
=x-x-4=-4
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