Find the y -coordinate of the solution of the following system. $\left\{ \begin{array} { l }
x + 7 y - 3 z = - 9 \
2 x - y + z = 6 \
- x + y - z = - 3
\end{array} \right.$
A) y=-3
B) y=-9
C) y=8
D) y=4

Question

Find the y -coordinate of the solution of the following system. $\left\{ \begin{array} { l } 
x + 7 y - 3 z = - 9 \
2 x - y + z = 6 \
- x + y - z = - 3
\end{array} \right.$
A) y=-3
B) y=-9
C) y=8
D) y=4

Quizplus · Accepted Answer

To find the y-coordinate, solve the system of equations. First, add the second and third equations to eliminate z: (2x - y + z) + (-x + y - z) = 6 - 3, which simplifies to x = 3. Substitute x = 3 into the second equation: 2(3) - y + z = 6, which simplifies to 6 - y + z = 6, so -y + z = 0, or z = y. Substitute x = 3 and z = y into the first equation: 3 + 7y - 3y = -9, which simplifies to 4y = -12, so y = -3.

Find the Y -Coordinate of the Solution of the Following {x+7y−3z=−92x−y+z=6−x+y−z=−3\left\{ \begin{array} { l } x + 7 y - 3 z = - 9 \\2 x - y + z = 6 \\- x + y - z = - 3\end{array} \right.⎩⎨⎧​x+7y−3z=−92x−y+z=6−x+y−z=−3​

Find the Y -Coordinate of the Solution of the Following $\left\{ \begin{array} { l } x + 7 y - 3 z = - 9 \\2 x - y + z = 6 \\- x + y - z = - 3\end{array} \right.$