Đưa thừa số ra ngoài dấu căn:\(a)\,\,\,\sqrt {180{...

Câu hỏi: Đưa thừa số ra ngoài dấu căn:\(a)\,\,\,\sqrt {180{x^2}} \\ b)\,\sqrt {3{x^2} - 6xy + 3{y^2}} \)

A \(\begin{array}{l}
a)\,\,6x\sqrt 5 \\
b)\,\,\,\left\{ \begin{array}{l}
\left( {x - y} \right)\sqrt 3 \,\,\,\,khi\,\,\,\,x \ge y\\
\left( {y - x} \right)\sqrt x \,\,\,\,khi\,\,\,x < y
\end{array} \right..
\end{array}\)

B \(\begin{array}{l}
a)\,\,\, - 6x\sqrt 5 \\
b)\,\,\left( {x - y} \right)\sqrt 3
\end{array}\)

C \(\begin{array}{l}
a)\,\,\left\{ \begin{array}{l}
6x\sqrt 5 \,\,\,khi\,\,\,x \ge 0\\
- 6x\sqrt 5 \,\,\,\,khi\,\,\,x < 0
\end{array} \right.\\
b)\,\,\,\left\{ \begin{array}{l}
\left( {x - y} \right)\sqrt 3 \,\,\,khi\,\,\,x \ge 0\\
\left( {y - x} \right)\sqrt 3 \,\,\,khi\,\,\,x < y
\end{array} \right..
\end{array}\)

D \(\begin{array}{l}
a)\,\, - 6x\sqrt 5 \\
b)\,\, - \left( {x - y} \right)\sqrt 3
\end{array}\)