Question

Giúp ;-; Giải chị tiết cho mình hiểu đc ko ạ ;-;

Answer 1

`1)\sqrt{[3a]/2}.\sqrt{[8a^3]/27}`      `(a >= 0)`

`=\sqrt{[3a.8a^3]/[2.27]}`

`=\sqrt{[24a^4]/54}=\sqrt{[(2 a^2)^2 .6]/[3^2 .6]}=[2a^2]/3`

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`2)\sqrt{2x^3}.\sqrt{8xy}.\sqrt{9y^5}`    `(x >= 0,y >= 0)`

`=\sqrt{2x^3 .8xy.9y^5}`

`=\sqrt{144x^4y^6}`

`=\sqrt{(12x^2y^3)^2}=|12x^2y^3|=12x^2y^3` (Vì `x >= 0,y >= 0`)

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`3)[x+\sqrt{xy}]/[y+\sqrt{xy}]`      `(x > 0,y > 0)`

`=[\sqrt{x}(\sqrt{x}+\sqrt{y})]/[\sqrt{y}(\sqrt{x}+\sqrt{y})]`

`=\sqrt{x}/\sqrt{y}`