Question

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Answer 1

70: Ta có: \(\dfrac{\left(\sqrt{5}+2\right)^2-8\sqrt{5}}{\sqrt{5}-2}\cdot\left(\sqrt{5}+2\right)\)

\(=\dfrac{9+4\sqrt{5}-8\sqrt{5}}{\sqrt{5}-2}\cdot\left(\sqrt{5}+2\right)\)

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

=5-4

=1