$\left\{\begin{matrix} 2x+\sqrt{2-x+y-x^{2}-y^{2}}=1 & \\ 2x^{3}=2y^{3}+1 & \end{matrix}\right.$
$\left\{\begin{matrix} 2x+\sqrt{2-x+y-x^{2}-y^{2}}=1 & \\ 2x^{3}=2y^{3}+1 & \end{matrix}\right.$
Started By thienthanaotrang, 30-01-2014 - 12:17
#1
Posted 30-01-2014 - 12:17
#2
Posted 30-01-2014 - 16:46
$\left\{\begin{matrix} 2x+\sqrt{2-x+y-x^{2}-y^{2}}=1 & \\ 2x^{3}=2y^{3}+1 & \end{matrix}\right.$hệ
bình phương PT(1) hệ tương đương
$\left\{\begin{matrix} 5x^2+y^2-3x-y-1=0\\ 2x^3-2y^3-1=0 \end{matrix}\right.$
$\Rightarrow 2x^3-2y^3=5x^2-3x+y^2-y\Leftrightarrow \left(x-y-1 \right)\left(2x^2-3x+2xy+2y^2-y \right)=0$
- etucgnaohtn and thienthanaotrang like this
1 user(s) are reading this topic
0 members, 1 guests, 0 anonymous users