$\left\{ \begin{array} { l }
2 x - 5 z + w = - 1 \
- x + 2 y + z - 2 w = 1 \
4 x - y + 5 w = - 2 \
y - 2 z - w = 0
\end{array} \right.$
A) x=-2, y=4, z=3, w=-5
B) x=4, y=-2, z=-7, w=-4
C) x=3, y=0, z=-1, w=0
D) x=4, y=-2, z=1, w=-4

Question

$\left\{ \begin{array} { l } 
2 x - 5 z + w = - 1 \
- x + 2 y + z - 2 w = 1 \
4 x - y + 5 w = - 2 \
y - 2 z - w = 0
\end{array} \right.$
A)  x=-2, y=4, z=3, w=-5 
B)  x=4, y=-2, z=-7, w=-4 
C)  x=3, y=0, z=-1, w=0 
D)  x=4, y=-2, z=1, w=-4

Quizplus · Accepted Answer

Substituting x=4, y=-2, z=1, w=-4 into each equation satisfies all four equations.

{2x−5z+w=−1−x+2y+z−2w=14x−y+5w=−2y−2z−w=0\left\{ \begin{array} { l } 2 x - 5 z + w = - 1 \\- x + 2 y + z - 2 w = 1 \\4 x - y + 5 w = - 2 \\y - 2 z - w = 0\end{array} \right.⎩⎨⎧​2x−5z+w=−1−x+2y+z−2w=14x−y+5w=−2y−2z−w=0​

$\left\{ \begin{array} { l } 2 x - 5 z + w = - 1 \\- x + 2 y + z - 2 w = 1 \\4 x - y + 5 w = - 2 \\y - 2 z - w = 0\end{array} \right.$