[Toán 10] Giải hệ phương trình

L

lp_qt

$\left\{\begin{matrix}(x-1)^{2}+(y+2)^{2}=9 & \\ xy(x-2)(y+4)+5=0 & \end{matrix}\right.$

\Leftrightarrow $\left\{\begin{matrix}x^{2}-2x+1+y^{2}+4y+4=9 & \\ x(x-1).y(y+4)=-5 &
\end{matrix}\right.$


đặt $\left\{\begin{matrix}a=x^{2}-2x & \\ b=y^{2}+4y & \end{matrix}\right.$

\Rightarrow $\left\{\begin{matrix}a+b=4 & \\ ab=-5 & \end{matrix}\right.$

\Leftrightarrow $\begin{bmatrix}\left\{\begin{matrix}a=5 & \\ b=-1 &
\end{matrix}\right. & \\ \left\{\begin{matrix}a=-1 & \\ b=5 & \end{matrix}\right. & \end{bmatrix}$
 
You must log in or register to reply here.
Top Bottom