Решите систему уравнений: x^2-2y=54; y=x-3.

\[x^{2} - 2x + 6 - 54 = 0\]

\[x^{2} - 2x - 48 = 0\]

\[D_{1} = 1 + 48 = 49\]

\[x_{1} = 1 + 7 = 8;\ \ \]

\[x_{2} = 1 - 7 = - 6.\]

\[\left\{ \begin{matrix}
x = 8 \\
y = 5 \\
\end{matrix} \right.\ \ \ \ или\ \ \ \ \left\{ \begin{matrix}
x = - 6 \\
y = - 9 \\
\end{matrix} \right.\ \]

\[Ответ:(8;5);( - 6; - 9).\]