Answer
The system has infinitely many solutions.
Work Step by Step
From equation (II), put the value of y in equation (I)
$\begin{align}
& 9x-3\left( 3x-4 \right)=12 \\
& 9x-9x+12=12 \\
\end{align}$
$12=12$ (III)
According to equation (III) $35=35$ indicates that the system has infinitely many solutions.
Thus, the system has infinitely many solutions.
