Giải hpt sau:
a)\(\left\{{}\begin{matrix}2\left(x^2-2x\right)+\sqrt{y+1}=0\\3\left(x^2-2x\right)-2\sqrt{y+1}+7=0\end{matrix}\right.\)
b)\(\left\{{}\begin{matrix}5\left|x-1\right|-3\left|y+2\right|=7\\2\sqrt{4x^2-8x+4}+5\sqrt{y^2+4y+4}=13\end{matrix}\right.\)
c)\(\left\{{}\begin{matrix}\dfrac{3x}{x+1}-\dfrac{2}{y+4}=4\\\dfrac{2x}{x+1}-\dfrac{5}{y+4}=9\end{matrix}\right.\)
d)\(\left\{{}\begin{matrix}\dfrac{x+1}{x-1}+\dfrac{3y}{y+2}=7\\\dfrac{2}{x-1}-\dfrac{5}{y+2}=4\end{matrix}\right.\)
Giải hệ \(\left\{{}\begin{matrix}2x^2=1+5xy+y^2\\y\left(\sqrt{y\left(x-2y\right)}+\sqrt{y\left(4y-x\right)}\right)=1\end{matrix}\right.\)
Giải hệ phương trình: \(\hept{\begin{cases}\sqrt{2x^2y^2-x^4y^4}=y^6+x^2\left(1-x\right)\\\sqrt{1+\left(x+y\right)^2}+x\left(2y^3+x^2\right)\le0\end{cases}}\)
\(\left\{{}\begin{matrix}8\sqrt{xy-2y}-8y+4=\left(x-y\right)^2\\2\sqrt{2y-y^2}\left(\sqrt{8-2x}-2\sqrt{2y}+1\right)=4y+5\sqrt{2-y}-10\sqrt{x-2}\end{matrix}\right.\)
giải hệ phương trình: \(\hept{\begin{cases}\left(2x+4y-1\right)\sqrt{2x-y-1}=\left(4x-2y-3\right)\sqrt{x+2y}\\x^2+8x+5-2\left(3y+2\right)\sqrt{4x-3y}=2\sqrt{2x^2+5x+2}\end{cases}}\)
Ghpt:
a) \(\left\{{}\begin{matrix}x^2+2y^2=2x-2xy+1\\3x^2+2xy-y^2=2x-y+5\end{matrix}\right.\)
b) \(\left\{{}\begin{matrix}4xy+4x^2+4y^2+\dfrac{3}{\left(x+y\right)^2}=7\\2x+\dfrac{1}{x+y}=3\end{matrix}\right.\)
Giải hệ
\(\hept{\begin{cases}5\left(x^2-2\right)=y^2-3y\\\left(6x+4y-1\right)\sqrt{x+y+1}=\left(2x+2y+1\right)\sqrt{3x+2y}\end{cases}}\)
\(P=x^4+y^4+x^4y^4+1=\left(\left(x+y\right)^2-2xy\right)^2-2x^2y^2+x^4y^4+1\)
\(=\left(10-2xy\right)^2-2x^2y^2+x^4y^4+1=x^4y^4+2x^2y^2-40xy+101\)
\(=\left(x^2y^2-4\right)^2+10\left(xy-2\right)^2+45\ge45\)
Dấu bằng tự xét
tìm cặp x, y tm:
\(\hept{\begin{cases}\sqrt{2x^2y-x^4y^2}-y^2+x^2\left(x-1\right)=0\\\sqrt{1+\left(x+y\right)^2}+x\left(2y+x^2\right)\le0\end{cases}}\)