Question 71
Solve the system
$$
\left\lvert\, \begin{aligned}
& 3 \cdot 4^{x}+2^{x+1} \cdot 3^{y}-9^{y}=0 \\
& 2 \cdot 4^{x}-5 \cdot 2^{x} \cdot 3^{y}+9^{y}=-8
\end{aligned}\right.
$$
$$
\left\lvert\, \begin{aligned}
& 3 \cdot 4^{x}+2^{x+1} \cdot 3^{y}-9^{y}=0 \\
& 2 \cdot 4^{x}-5 \cdot 2^{x} \cdot 3^{y}+9^{y}=-8
\end{aligned}\right.
$$