để mk làm nốt cho
\(y^4-2y^3+2y^2-y-2=0\)
<=> \(\left(y^4-2y^3+y^2\right)+\left(y^2-y\right)-2=0\)
<=> \(\left(y^2-y\right)^2+\left(y^2-y\right)-2=0\)
đặt y^2-y=t thì ta có pt \(t^2+t-2=0\)
<= >\(\int_{t=-2}^{t=1}\)
với t=1==> \(y^2-y=1\) từ đó tính ra nghiệm x=\(\frac{1+\sqrt{5}}{2}\) và \(x=\frac{1-\sqrt{5}}{2}\)
với t=-2 thì pt vô nghiệm
Mn giúp e với ạ lm đc con nào thì làm ạ e cần gấp :((
\(1.\begin{cases}x^4+4x^3+y^2=8\\-4x^3+2x^2+xy\left(y-2\right)=-4\end{cases}\) 5.\(\begin{cases}xy^3+y^3+xy+y=1\\4x^2y^3-4y^3-8xy-17+8=0\end{cases}\)
\(2.\begin{cases}2x^2y^2+x^2+2x=2\\2x^2y-x^2y^2+2xy=1\end{cases}\) 6.\(\begin{cases}2x+\frac{5y}{x^2+y^2}=4\\2y+\frac{5x}{x^2+y^2}=5\end{cases}\)3.\(\begin{cases}x^2+4y=3\\\left(2y^2+1\right)x=y^4+y^2-4y+1\end{cases}\)
4.\(\begin{cases}x^3+y^3-x^2y-xy^2-xy=0\\y^2-3x^2+3xy+3x-y-1=0\end{cases}\)
giúp mik giải bài hệ pt vs ạ!
1,\(\left\{{}\begin{matrix}x^2+y^2+\dfrac{2xy}{x+y}=1\\\sqrt{x+y}=x^2-y\end{matrix}\right.\)
2,\(\left\{{}\begin{matrix}2x^3+xy^2+x=y^3+4x^2y+2y\\\sqrt{4x^2+x+6}-5\sqrt{1+2y}=1-4y\end{matrix}\right.\)
3,\(\left\{{}\begin{matrix}2x^2+\sqrt{2}x=\left(x+y\right)y+\sqrt{x+y}\\\sqrt{x-1}+xy=\sqrt{y^2+21}\end{matrix}\right.\)
4,\(\left\{{}\begin{matrix}\sqrt{9y^2+\left(2y+3\right)\left(y-x\right)}+4\sqrt{xy}=7x\\\left(2y-1\right)\sqrt{1+x}+\left(2y+1\right)\sqrt{1-x}=2y\end{matrix}\right.\)
1)\(\begin{cases}x+\sqrt{x^2+1}=y+\sqrt{y^2-1}\left(1\right)\\3\sqrt{y-1}+\sqrt{x}=2\sqrt{y+1}\left(2\right)\end{cases}\) nhân liên hợp pt 1 đc (\(\left(x^2-y^2+1\right)\left(\frac{1}{x+\sqrt{y^2-1}}+\frac{1}{\sqrt{x^2+1}+y}\right)\) thì TH1 \(x^2-y^2+1\) lm ntn
2\(\begin{cases}\sqrt{x^2+xy+2y^2}+\sqrt{xy}=3y\\\sqrt{y-1}+\sqrt{x-1}+x+y=6\end{cases}\)
3\(\begin{cases}\frac{\sqrt{x^2+5}}{x}+\frac{\sqrt{y^2+3}}{y}=\frac{7}{2}\\x\sqrt{x^2+5}+y\sqrt{y^2+3}=3+x^2+y^2\end{cases}\)
Giúp mình với, thanks các bạn nhiều: ^^ BT/ Giải hệ pt:
1/\(\left\{{}\begin{matrix}x^3+y^3=1\\x^2y+2xy^2+y^3=2\end{matrix}\right.\) 2/\(\left\{{}\begin{matrix}y^2=\left(x+8\right).\left(x^2+2\right)\\y^2-4\left(x+2\right)y+16+16x-5x^2=0\end{matrix}\right.\)
3/\(\left\{{}\begin{matrix}x^2-3x\left(y-1\right)+y^2+y\left(x-3\right)=4\\x-xy-2y=1\end{matrix}\right.\) 3/\(\left\{{}\begin{matrix}\sqrt{x}-\sqrt{x-y-1}=1\\y^2+x+2y\sqrt{x}-xy^2=0\end{matrix}\right.\)
giải giúp mik bt này vs mn!
1)\(\left\{{}\begin{matrix}2x^2+y^2+x=3\left(xy+1\right)+2y\\\dfrac{2}{3+\sqrt{2x-y}}+\dfrac{2}{3+\sqrt{4-5x}}=\dfrac{9}{2x-y+9}\end{matrix}\right.\)
2)\(\left\{{}\begin{matrix}\left(x+3y+1\right)\sqrt{2xy+2y}=y\left(3x+4y+3\right)\\\left(\sqrt{x+3}-\sqrt{2y-2}\right)\left(x-3+\sqrt{x^2+x+2y-4}\right)=4\end{matrix}\right.\)
3)\(\left\{{}\begin{matrix}x-\dfrac{1}{x}=y-\dfrac{1}{y}\\2y=x^3+1\end{matrix}\right.\)
4)\(\left\{{}\begin{matrix}\sqrt{2x-3}=\left(y^2+2011\right)\left(5-y\right)+\sqrt{y}\\y\left(y-x+2\right)=3x+3\end{matrix}\right.\)
5)\(\left\{{}\begin{matrix}x^3+2x^2=x^2y+2xy\\2\sqrt{x^2-2y-1}+\sqrt[3]{y^3-14=x-2}\end{matrix}\right.\)
1)\(\begin{cases}\left(8x-6\right)\sqrt{y}=\left(2+\sqrt{x-2}\right)\left(y+4\sqrt{x-2}+4\right)\\2\sqrt{x^2+3x-y}-\sqrt{y^2+4x}=x+1\end{cases}\)
2)\(\begin{cases}\left(x+\sqrt{x^2+1}\right)\left(y+\sqrt{y^2+1}\right)=1\\x^2+\sqrt{3-x}=2y^2-4\sqrt{2-y}+5\end{cases}\)
giải hệ phương trình
1 , \(\left\{{}\begin{matrix}\left(x+y\right)\left(x-1\right)=\left(x-y\right)\left(x+1\right)+2xy\\\left(y-x\right)\left(y-1\right)=\left(y+x\right)\left(y-2\right)-2xy\end{matrix}\right.\)
2, \(\left\{{}\begin{matrix}2\left(\frac{1}{x}+\frac{1}{2y}\right)+3\left(\frac{1}{x}-\frac{1}{2y}\right)^2=9\\\left(\frac{1}{x}+\frac{1}{2y}\right)-6\left(\frac{1}{x}-\frac{1}{2y}\right)^2=-3\end{matrix}\right.\)
3 , \(\left\{{}\begin{matrix}\frac{xy}{x+y}=\frac{2}{3}\\\frac{yz}{y+z}=\frac{6}{5}\\\frac{zx}{z+x}=\frac{3}{4}\end{matrix}\right.\)
4 , \(\left\{{}\begin{matrix}2xy-3\frac{x}{y}=15\\xy+\frac{x}{y}=15\end{matrix}\right.\)
5 , \(\left\{{}\begin{matrix}x+y+3xy=5\\x^2+y^2=1\end{matrix}\right.\)
6 , \(\left\{{}\begin{matrix}x+y+xy=11\\x^2+y^2+3\left(x+y\right)=28\end{matrix}\right.\)
7, \(\left\{{}\begin{matrix}x+y+\frac{1}{x}+\frac{1}{y}=4\\x^2+y^2+\frac{1}{x^2}+\frac{1}{y^2}=4\end{matrix}\right.\)
8, \(\left\{{}\begin{matrix}x+y+xy=11\\xy\left(x+y\right)=30\end{matrix}\right.\)
9 , \(\left\{{}\begin{matrix}x^5+y^5=1\\x^9+y^9=x^4+y^4\end{matrix}\right.\)
Giải hpt
\(\begin{cases}5x^2y-4xy^2+3y^3-2\left(x+y\right)=0\\xy\left(x^2+y^2\right)+2=\left(x+y\right)^2\end{cases}\)
Giải hệ pt:
\(\begin{cases}x^3-\left(y^2+y\right)^3=y^3\left(\sqrt{y+1}-\sqrt{\frac{x}{y}}\right)\\2x^3-12y^3=xy^2\left(1+y\right)\end{cases}\)