Use the elimination method to find all solutions of the system:
\begin{cases} 3x^2 - y^2 = 11 \\ x^2 + 4y^2 = 8 \end{cases}
The four solutions of the system are:
Enter your answer as a list of ordered pair. For example: (2, -5), (5, -2), (1, 3), (3, 1)