[tex]2(x-y)^2+6y-2x+4=x+y+1+2\sqrt{xy+x}<=>2(x-y)^2+5y-5x+3=2\sqrt{xy+x}-2x<=>2(x-y)^2-4(x-y)+2+y-x+1=2\sqrt{xy+x}-2x<=>2(x-y-1)^2-(x-y-1)=2\frac{x(y+1-x)}{\sqrt{xy+x}+x}<=>=>x-y-1=0 \vee 2(x-y-1)-1=\frac{2x}{\sqrt{xy+x}+x}[/tex]
[tex]2(x-y-1)-1=\frac{-2x}{\sqrt{xy+x}+x}=>x=\sqrt{x};\sqrt{y+1}=b=>2(a^2-b^2)-1=\frac{-2a}{b+a}<=>2(a-b)(a+b)^2-a-b=-2a<=>2(a-b)(a+b)^2+a-b=0<=>a=b\vee 2(a+b)^2+1=0(false )[/tex]
=>x=y+1
thay lên ta được [tex]\sqrt{3-y}-y-2+\sqrt{y+8}-y-3=y^2+5y+1<=>\frac{-y^2-5y-1}{\sqrt{3-y}+y+2}+\frac{-y^2-5x-1}{\sqrt{y+8}+y+3}=y^2+5y+1=>y^2+5y+1=0\vee \frac{1}{\sqrt{3-y}+y+2}+\frac{1}{\sqrt{y+8}+y+3}+1=0(false)[/tex]
=>[tex]y^2+5y+1=0[/tex]=>y=>x