$\left\{\begin{matrix} \sqrt{3x+y}+\sqrt{5x+4y}=5\\ 12\sqrt{5x+4y}+x-2y=35 \end{matrix}\right.$
$\left\{\begin{matrix} \sqrt{3x+y}+\sqrt{5x+4y}=5\\ 12\sqrt{5x+4y}+x-2y=35 \end{matrix}\right.$
Started By lilolilo, 12-03-2014 - 15:29
#1
Posted 12-03-2014 - 15:29
#2
Posted 12-03-2014 - 15:32
$\left\{\begin{matrix} \sqrt{3x+y}+\sqrt{5x+4y}=5\\ 12\sqrt{5x+4y}+x-2y=35 \end{matrix}\right.$
Đặt $a=\sqrt{3x+y};b=\sqrt{5x+4y}\rightarrow x-2y=2a^{2}-b^{2}\rightarrow \left\{\begin{matrix} a+b=5 & & \\ 12b+2a^{2}-b^{2}=35& & \end{matrix}\right.$
Đến đây là được rồi
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