Bài 1:
$\left\{\begin{matrix} x^{2}+y^{2}=3x-4y+1 & & \\ 3x^{2}(x^{2}+9)-2y^{2}(y^{2}+9)=18(x^{3}+y^{3})+2y^{2}(7-y)+3 & & \end{matrix}\right.$
Bài 2:
$\left\{\begin{matrix} \log _{\frac{\sqrt{3}}{2}}y-\log _{\frac{\sqrt{3}}{2}}x=(x-y)(x^{2}-xy+y^{2}) & & \\ x^{2}+y^{2}=4 & & \end{matrix}\right.$