Giải hệ phương trình:
a) \(\left\{{}\begin{matrix}\sqrt{3y^2+13}-\sqrt{15-2x}=\sqrt{x+1}\\y^4-2x^2y+7y^2=\left(x+1\right)\left(8-x\right)\end{matrix}\right.\)
b) \(\left\{{}\begin{matrix}\sqrt{x+y}-\sqrt{x-y}=2\\\sqrt{x^2+y^2+1}-\sqrt{x^2-y^2}=3\end{matrix}\right.\)
c) \(\left\{{}\begin{matrix}\sqrt{2x+y+1}-\sqrt{x+y}=3\\\sqrt{3\left(x+y\right)^2+1}+\sqrt{x-5}=5\end{matrix}\right.\)
Giải hệ phương trình:
a) \(\left\{{}\begin{matrix}x^2+y^2+\dfrac{1}{x^2}+\dfrac{1}{y^2}=5\\\left(xy-1\right)^2=x^2-y^2+2\end{matrix}\right.\)
b) \(\left\{{}\begin{matrix}x,y,z>0\\\dfrac{1}{x}+\dfrac{9}{y}+\dfrac{16}{z}=9\\x+y+z\le4\end{matrix}\right.\)
c)\(\left\{{}\begin{matrix}x+y+z=3\\x^4+y^4+z^4=3xyz\end{matrix}\right.\)