Найдите решение системы: x+y+z=1; x-y=2; y+z=3.

\[\left\{ \begin{matrix}
x + y + z = 1 \\
x - y = 2\ \ \ \ \ \ \ \\
y + z = 3\ \ \ \ \ \ \ \ \\
\end{matrix} \right.\ \text{\ \ \ \ \ \ }\]

\[\left\{ \begin{matrix}
x - y = 2 \\
y + z = 3 \\
x + 3 = 1 \\
\end{matrix} \right.\ \text{\ \ \ \ \ \ }\]

\[\left\{ \begin{matrix}
x = - 2\ \ \ \ \\
y = x - 2 \\
z = 3 - y \\
\end{matrix} \right.\ \text{\ \ \ \ \ }\]

\[\left\{ \begin{matrix}
x = - 2\ \ \ \ \ \ \ \\
y = - 2 - 2 \\
z = 3 - y\ \ \ \\
\end{matrix} \right.\ \]

\[\ \left\{ \begin{matrix}
x = - 2\ \ \ \ \ \ \ \ \ \ \ \\
y = - 4\ \ \ \ \ \ \ \ \ \ \ \\
z = 3 - ( - 4) \\
\end{matrix} \right.\ \text{\ \ \ \ \ \ \ \ \ \ }\]

\[\left\{ \begin{matrix}
x = - 2 \\
y = - 4 \\
z = 7\ \ \ \ \\
\end{matrix} \right.\ \]

\[Ответ:( - 2;\ - 4;7).\]