Question

Cât face 5 radical din 20 ?

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Answer 1

$5\sqrt{20}=\sqrt{5^2\cdot20}=\sqrt{25\cdot20}=\sqrt{500}\\\sqrt{484}\leq \sqrt{500} < \sqrt{529}\\22\leq \sqrt{500}\leq 23$

Answer 2

$\it 5\sqrt{20}=5\sqrt{4\cdot5}=5\cdot2\sqrt5=10\sqrt5$