a/ \(x\ge-3\)
\(4x^2+x+2-4x\sqrt{x+3}=0\)
\(\Leftrightarrow\left(2x\right)^2-2.2x\sqrt{x+3}+x+3-1=0\)
\(\Leftrightarrow\left(2x-\sqrt{x+3}\right)^2-1=0\)
\(\Leftrightarrow\left(2x-1-\sqrt{x+3}\right)\left(2x+1-\sqrt{x+3}\right)=0\)
\(\Leftrightarrow\left[{}\begin{matrix}2x-1=\sqrt{x+3}\\2x+1=\sqrt{x+3}\end{matrix}\right.\) \(\Leftrightarrow...\) bạn giải tiếp
b/ \(\left\{{}\begin{matrix}y^3-1=-x^2\\x^2+y^2\left(y^3-1\right)=x^3\end{matrix}\right.\)
\(\Rightarrow x^2-x^2y^2-x^3=0\Leftrightarrow x^2\left(1-y^2-x\right)=0\) \(\Leftrightarrow\left[{}\begin{matrix}x=0\Rightarrow y=1\\x=1-y^2\left(1\right)\end{matrix}\right.\)
Thế (1) vào pt đầu
\(\left(1-y^2\right)^2+y^3=1\Leftrightarrow y^4-2y^2+y^3=0\)
\(\Leftrightarrow y^2\left(y^2+y-2\right)=0\) \(\Rightarrow y=...\) \(\Rightarrow x=...\)
