Question

a/ đưa các thừa số ra ngoài dấu căn :

1/\(\sqrt{27x^2}(x>0)\)

2/\(\sqrt{8xy^2}(x\ge0;y\le0)\)

b/ đưa thừa số vào trong dấu căn :

1/\(x\sqrt{13}(x\ge0)\)

2/\(x\sqrt{-15x}(x< 0)\)

3/\(x\sqrt{2}(x\le0)\)

Answer 1

a) \(\sqrt{27x^2}=\sqrt{3.\left(3x\right)^2}=\left|3x\right|.\sqrt{3}=3x\sqrt{3}\left(x>0\right)\)

b) \(\sqrt{8xy^2}=\left|y\right|.2\sqrt{2x}=-2y\sqrt{2x}\left(x\ge0,y\le0\right)\)

1) \(x\sqrt{13}=\sqrt{13x^2}\left(x\ge0\right)\)

2) \(x\sqrt{-15x}=-\left|x\right|\sqrt{15x}=-\sqrt{15x^3}\left(x< 0\right)\)

3) \(x\sqrt{2}=-\left|x\right|\sqrt{2}=-\sqrt{2x^2}\left(x\le0\right)\)