1.[tex]\left\{\begin{matrix} x(x-3)-3y(y+1)=-2\\ 2x(x-3)+y(y+1)=10 \end{matrix}\right.[/tex]
Gợi ý:
Đặt [tex]x(x-3)=a; y(y+1)=b\Rightarrow HPT\Leftrightarrow \left\{\begin{matrix} a-3b=-2 & & \\ 2a+b=10 & & \end{matrix}\right.\Rightarrow a;b=..\Rightarrow x;y=...[/tex]