pt(1)$\Leftrightarrow$$\frac{6x}{y}$-2-$\sqrt{3x-y}$-3y=0$\Leftrightarrow$$\frac{2(3x-y)}{y^{2}}$-$\frac{\sqrt{3x-y}}{y}$-3=0
Đặt t=$\frac{\sqrt{3x-y}}{y}$$\Rightarrow$2$t^{2}$-t-3=0$\Rightarrow$t=$\frac{3}{2}$ or t=-1
TH1:t=$\frac{3}{2}$$\Rightarrow$$\frac{\sqrt{3x-y}}{y}$=$\frac{3}{2}$$\Rightarrow$$\sqrt{3x-y}$=$\frac{3}{2}$y(y$\geq$0)(1)
Thế(1) vào pt(2) ta đc:2$\sqrt{3x+\frac{3}{2}y}$=6x+3y-4$\Leftrightarrow$6x+3y-$\sqrt{2}$.$\sqrt{6x+3y}$-4=0
Đặt u=$\sqrt{6x+3y}$(u$\geq$0)$\Rightarrow$u=2$\sqrt{2}$(t/m) or u=-$\sqrt{2}$(L)
$\Rightarrow$$\sqrt{6x+3y}$=2$\sqrt{2}$(2)
Kết hợp (1)&(2)$\Rightarrow$(x;y)=($\frac{8}{9}$;$\frac{8}{9}$)
TH2:t=-1.
Làm tương tự:$\Rightarrow$(x;y)=...