Question

By substituting \(x + y = S\) and \(xy = P^2\), or otherwise, solve the simultaneous equations \[\begin{align*} x + y + \sqrt{\vphantom{1}xy} &= 39, \\ x^2 + y^2 + xy &= 741. \end{align*}\]

The expression \(\sqrt{\vphantom{1}xy}\) denotes the positive square root of \(xy\).