H
hongha111


Mã:
[tex]\left\{ \begin{array}{l} 4^x-5.2^{x+y}+4^{y+1}= 0 \\ x^2-xy+y^2=1 \end{array} \right.[/tex]
[tex]\left\{ \begin{array}{l} 4^x-5.2^{x+y}+4^{y+1}= 0 \\ x^2-xy+y^2=1 \end{array} \right.[/tex]