\(\Leftrightarrow\left\{{}\begin{matrix}\left(\sqrt{5}+2\right)x+y=3-\sqrt{5}\\x=2y-6+2\sqrt{5}\end{matrix}\right.\)
\(\Leftrightarrow\left\{{}\begin{matrix}\left(\sqrt{5}+2\right)\left(2y-6+2\sqrt{5}\right)+y=3-\sqrt{5}\\x=2y-6+2\sqrt{5}\end{matrix}\right.\)
\(\Leftrightarrow\left\{{}\begin{matrix}2\sqrt{5}y+4y-6\sqrt{5}-12+10+4\sqrt{5}+y=3-\sqrt{5}\\x=2y-6+2\sqrt{5}\end{matrix}\right.\)
\(\Leftrightarrow\left\{{}\begin{matrix}5y+2\sqrt{5}y=5\sqrt{5}\\x=2y-6+2\sqrt{5}\end{matrix}\right.\)
\(\Leftrightarrow\left\{{}\begin{matrix}x=0\\y=3-\sqrt{5}\end{matrix}\right.\)
Vậy...........
