Giải HPT :
- $\left\{\begin{matrix} x^2-y^2+xy=1 & & \\ 3x+y=y^2+3 & & \end{matrix}\right.$
- $\left\{\begin{matrix} x^2+y^2=2x & & \\ (x-1)^3+y^3=1 & & \end{matrix}\right.$
- $\left\{\begin{matrix} x+y=\sqrt{4z-1} & & & \\ y+z=\sqrt{4x-1} & & & \\ x+z=\sqrt{4y-1} & & & \end{matrix}\right.$
- $\left\{\begin{matrix} x^2-3x=y & & \\ y^2-3y=x & & \end{matrix}\right.$
- *$\left\{\begin{matrix} y=\frac{2x^2}{x^2+1} & & & \\ z=\frac{3y^3}{y^4+y^2+1} & & & \\ x=\frac{4z^4}{z^6+z^4+z^2+1} & & & \end{matrix}\right.$