Question 94
Determine all ordered triplets of real numbers $(x, y, z)$ such that
$$
\begin{cases}
x + y = \sqrt{28} \\
xy - 2z^2 = 7.
\end{cases}
$$
$$
\begin{cases}
x + y = \sqrt{28} \\
xy - 2z^2 = 7.
\end{cases}
$$
MathNet 2013 Question 94
Math Olympiad Vault · MathNet 2013