Question

[Trinh Tuyết Na]

1,\(\left\{{}\begin{matrix}x-y^2+1=0\\\sqrt{y^2+3}+x=2\end{matrix}\right.\)

2,\(\left\{{}\begin{matrix}x^4+2x^3y+x^2y^2=2x+9\\x^2+2xy=6x+6\end{matrix}\right.\)

3,\(\left\{{}\begin{matrix}xy+x-2=0\\2x^3-x^2y+x^2+y^2-2xy-y=0\end{matrix}\right.\)

Answer 1

[Huyền]

1,\(\left\{{}\begin{matrix}x=y^2-1\\\sqrt{y^2+3}+y^2-1=2\end{matrix}\right.\)

\(\Leftrightarrow\left\{{}\begin{matrix}x=y^2-1\\\sqrt{y^2+3}+y^2+3-6=0\end{matrix}\right.\)

\(\Leftrightarrow\left\{{}\begin{matrix}x=y^2-1\\\left(\sqrt{y^2+3}-2\right)\left(\sqrt{y^2+3}+3\right)=0\end{matrix}\right.\)

\(\Leftrightarrow\left\{{}\begin{matrix}x=y^2-1=0\\y^2=1\end{matrix}\right.\)\(\Leftrightarrow\left\{{}\begin{matrix}x=0\\y=\pm1\end{matrix}\right.\)