Question

$2 .\sqrt[3]{343} + \sqrt[3]{125}\\-------\\\\\sqrt{5}$

Será um número positivo, irracional ou racional?

Answer 1

Resposta:

${2.\sqrt[3]{343} +\sqrt[3]{125} \over\sqrt{5} }=\\ \\ {2.\sqrt[3]{7^3} +\sqrt[3]{5^3} \over\sqrt{5} }=\\ \\ {2.(7)+5\over\sqrt{5} }=\\ \\ {14+5\over\sqrt{5} }={19\over\sqrt{5}}\\ \\  racionalizar~~sendo~~\sqrt{5} ~~fator~~racionalizante\\ \\ {19\sqrt{5} \over\sqrt{5} .\sqrt{5} }={19\sqrt{5} \over\sqrt{25} }=\fbox{ {19\sqrt{5} \over5} }$