\(\sqrt{x}+\sqrt{y}+\sqrt{xy}+1\)
\(=\sqrt{x}+\sqrt{y}+\sqrt{x}.\sqrt{y}+1\)
\(=\sqrt{x}\left(\sqrt{y}+1\right)+\left(\sqrt{y}+1\right)\)
\(=\left(\sqrt{x}+1\right)\left(\sqrt{y}+1\right)\)
( căn x + 1 ) + ( căn y + căn xy )
( căn x + 1 ) + căn y.( căn x + 1)
( căn x +1 )(căn y + 1 )