Find the Y -Coordinate of the Solution of the System $\left\{ \begin{array} { l } x - y - 2 z = 15 \\3 x + 2 y - z = 20 \\x - y + z = 9\end{array} \right.$

Multiple Choice

Find the y -coordinate of the solution of the system $\left\{ \begin{array} { l } x - y - 2 z = 15 \\3 x + 2 y - z = 20 \\x - y + z = 9\end{array} \right.$

A) y=3
B) y=-3
C) y=-8
D) y=-2