Question

12. Efetue as multiplicações e simplifique os resultados:

$a)\sqrt{15}.\sqrt{3} \\ b)\sqrt{98}. \sqrt{2}$
$c)\sqrt[5]{8}.\sqrt[5]{4} \\ d) \sqrt[3]{25}. \sqrt[3]{5}$
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Answer 1

$a)\\\sqrt{15}\sqrt{3}\\\\=\sqrt{3\cdot \:5}\sqrt{3}\\\\=\sqrt{3}\sqrt{5}\sqrt{3}\\\\\sqrt{3}\sqrt{3}=3\\\\=3\sqrt{5}$  

$b)\\\sqrt{98}\sqrt{2}\\\\=\sqrt{98\cdot \:2}\\\\98\cdot \:2=196\\\\=\sqrt{196}\\\\=14$

$c)\\\sqrt[5]{8}\sqrt[5]{4}\\\\=\sqrt[5]{8\cdot \:4}\\\\=\sqrt[5]{32}\\\\=2$

$d)\\\sqrt[3]{25}\sqrt[3]{5}\\\\=\sqrt[3]{25\cdot \:5}\\\\=\sqrt[3]{125}\\\\=5$