Giải hpt:
1. $\left\{\begin{matrix} x^2-y^2-2x+2y+3=0 & \\ x^2-2xy+2y+7=0 & \end{matrix}\right.$
2. $\left\{\begin{matrix} \frac{x^2+y^2}{xy(x+y)}+2=\frac{(x+y)^4}{xy} & \\ 4\sqrt{3-y}+\sqrt{22-3x}=x^2+8 & \end{matrix}\right.$
3. $\left\{\begin{matrix} x^2+4y^2-4x+12y+11=0 & \\ x^2+4y^2-2xy-x+4y-12=0 & \end{matrix}\right.$