Answer:
option C
x = 6
y = 4
z = 1
Step-by-step explanation:
Given in the question a matrix in the row echelon form of the augmented matrix.
[tex]\left[\begin{array}{ccc}1&0&+4=-1\\0&1&-1=+3\\0&0&+1=+1\end{array}\right][/tex]
First Equation
x0 + y0 + z(1) = 1
0 + 0 + z = 1
z = 1
Second Equation
x0 + y(1) + z(-1) = 3
0 + y - z = 3
y -1 = 3
y = 4
Third Equation
x(1) + y0 + z(4) = -1
x + 0 + 4z = -1
x + 4 = -1
x = -5
