B

9000019907

Level: 
B
The augmented matrix of a system of three equations with three unknowns is row equivalent with the following matrix \(A'\). Find the solution of the system. \[ A' = \left(\begin{array}{ccc|c} 1 & 2 & 4 & 0\\ 0 & 2 & 7 & 7\\ 0 & 0 & 7 & 35 \end{array}\right) \]
\([8,-14,5]\)
\([-62,21,5]\)
\([8,14,-5]\)
\([-22,-21,5]\)

9000019908

Level: 
B
The augmented matrix of a system of three equations with three unknowns is row equivalent with the following matrix \(A'\). Find the solution of the system. \[ A' = \left(\begin{array}{ccc|c} -1 & 0 & 1 &-1\\ 0 & 7 & 2 & -1\\ 0 & 0 & 30 & 6 \end{array}\right) \]
\(\left [\frac{6} {5},-\frac{1} {5}, \frac{1} {5}\right ]_{}\)
\(\left [\frac{1} {5},-\frac{1} {5}, \frac{6} {5}\right ]\)
\(\left [\frac{1} {5},-\frac{6} {5},-\frac{1} {5}\right ]\)
\(\left [-\frac{6} {5}, \frac{1} {5}, \frac{1} {5}\right ]\)

9000019910

Level: 
B
The augmented matrix of a system of three equations with three unknowns is row equivalent to the following matrix \(A'\). Find the solution of the system. \[ A' = \left(\begin{array}{ccc|c} -1 & -6 & 1 &-20\\ 0 & 5 & 4 & -12\\ 0 & 0 & 0 & -8 \end{array}\right) \]
no solution
\(\left [-\frac{172} {5} ,-\frac{12} {5} ,0\right ]\)
\([-12t,4t,-8t],\ t\in \mathbb{R}\)
\(\left [-12,4,-8\right ]\)