\begin{tabular}{|l|l|} \hline & \begin{tabular}{l} The system has no solution. \\ The system has a unique solution: \\ $(x, y)=(\square, \square)$ \\ System A \\ $2 x-y=6$ \end{tabular} \\ The system has infinitely many solutions. \\ They must satisfy the following equation: \\ $y=6$ \end{tabular}

Step 1 ：The system of equations given is System A: \(2x - y = 6\) and \(y = 6\).

Step 2 ：To find the solution to this system, we can substitute \(y = 6\) into the first equation and solve for \(x\).

Step 3 ：Substituting \(y = 6\) into the first equation gives us \(2x - 6 = 6\).

Step 4 ：Solving this equation gives us the solution \(x = 6\).

Step 5 ：Therefore, the solution to the system of equations is \((x, y) = (6, 6)\).

Step 6 ：Final Answer: \(\boxed{(6, 6)}\)